1

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

PC Code No.: 085651

DP Barcode: D396052

Date: February 10, 2012

MEMORANDUM

SUBJECT: Estimated Drinking Water Concentrations of Cyazofamid and its Degradates of 

Concern CCIM, CCIM-AM and CTCA, for Use in Human Health Risk 

Assessment: IR-4 Petition for the Use on Succulent Beans, Shelled Beans, Leafy

Greens Subgroup 4A, Basil (Fresh and Dried Leaves), Tuberous and Corm 

Vegetables Subgroup 1C, and Fruiting Vegetables Group 8-10

TO: Laura Nollen, Risk Manager Reviewer

Barbara Madden, Team Leader

Daniel Rosenblatt, Chief

Risk Integration, Minor Use and Emergency Response Branch

Registration Division (7505P)

AND: Paula Deschamp, Chief

Registration Action Branch III

Health Effects Division (7509P)

FROM: José L. Meléndez, Chemist

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

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

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

This memorandum presents the Estimated Drinking Water Concentrations (EDWCs) for the 

fungicide cyazofamid, and for its major transformation products CCIM, CCIM-AM and CTCA, 

for use in the human health risk assessment. An IR-4 request for registration of several new 

crops was submitted to the Agency, including succulent beans, shelled beans, leafy greens 

Subgroup 4A, basil (fresh and dried leaves), tuberous and corm vegetables Subgroup 1C, and 

fruiting vegetables Group 8-10 (some fruiting vegetables have been previously registered). 

Based on a review of the use information, it was found that the proposed new crops have much 
2

lower seasonal application rates than turf and ornamentals. The highest seasonal rates among the 

newly proposed crops belong to basil and tuberous and corm vegetables at ~0.7 lb a.i./A/season, 

compared to 3.0 – 3.12 lb a.i./A/season for turf and ornamentals (Table 1-2). EDWCs for the 

new uses should be smaller than those already calculated for turf and ornamentals; therefore, a 

new drinking waters assessment (DWA) is not required. The values reported in the previous 

assessment can be used to cover the new crops.

A copy of the last DWA, dated March 24, 2009, is provided in Attachment A, which also 

provides structures and nomenclature of cyazofamid and its transformation products. Moreover, 

a copy of the DWA dated September 6, 2006, in which turf and ornamentals were modeled is 

included in Attachment B. These attachments provide specific information about the chemicals

modeled (cyazofamid, CCIM and CCIM-AM for acute exposure and CTCA for chronic 

exposure), structures, problem formulation and approach taken in modeling the crops, a 

summary of physicochemical and environmental fate properties of the chemicals, etc.

The Health Effects Division (HED) Metabolism Assessment Review Committee (MARC) 

concluded that cyazofamid and the metabolites designated as CCIM, CCIM-AM and CTCA 

should be considered to be the major residues in water and should be included in the drinking 

waters assessment (Acierto et al. 2004, DP Barcode D298915).

1

As summarized in Table 1-1, the surface water acute EDWC is 38.2 ppb. The surface water 

non-cancer chronic value is 133.5 ppb and the cancer chronic EDWC is 77.3 ppb. The value for 

ground water is 2.18 ppb, which is suitable for both acute and chronic exposures. The above 

stated values represent upper-bound estimates of the parent and individual degradates’ 

concentrations that might be found in surface water and groundwater due to the use of 

cyazofamid on turf and ornamentals, as reported previously in DP Barcodes D319466 and 

D356839 (see Attachments A & B). It is noted that this is still a screening-level analysis. 

Should any questions arise, please, contact EFED.

Table 1-1. Maximum Estimated Drinking Water Concentrations for Cyazofamid, CCIM, CCIMAM and CTCA. Maximum EDWCs are Based on the Use on Turf and Ornamentals Previously 

reported in D319466 (Dated 09/06/2006, Attachment B)

DRINKING WATER SOURCE

(Model Used) USE (rate modeled per year)

MAXIMUM ESTIMATED DRINKING WATER 

CONCENTRATION (EDWC) ( ppb)

Groundwater

(SCI-GROW) Ornamentals (3.12 lb a.i./A/yr) Acute and Chronic 2.181

Surface water

(PRZM/ EXAMS)

Turf & Ornamentals

(3.0 & 3.12 lb a.i./A/yr, respectively)

Acute 38.22

Chronic 133.51

Cancer/Chronic 77.31

1. Acute exposure is based on modeling of the parent cyazofamid and the degradates CCIM and CCIM-AM.

2. Chronic exposure is based on modeling of the degradate CTCA (includes acute exposure in SCI-GROW).

 

1 Acierto, A., et al. Cyazofamid - Meeting Report of the Metabolism Assessment Review Committee (MARC), Health 

Effects Division Memo dated 02/18/2004; DP Barcode D298915.
3

Use information:

There are two products that contain cyazofamid, both of which are flowable suspensions (SC): 

Ranman®400SC Fungicide label (EPA Reg. No. 71512-3) and Cyazofamid 400SC Turf and 

Ornamentals (EPA Reg. No. 71512-13). The chemical is currently used on crops like potatoes, 

cucurbit vegetables, turf, ornamentals, carrots, fruiting vegetables & okra, and grapes (East of the 

Rocky Mountains) (Table 1-2). An IR-4 petition for registration of several new crops was 

submitted to the Agency, including succulent beans, shelled beans, leafy greens Subgroup 4A, 

basil (fresh and dried leaves), tuberous and corm vegetables Subgroup 1C, and fruiting 

vegetables Group 8-10 as shown in Table 1-2. The maximum seasonal rates for the new crops

range from 0.43 lb a.i./A/season for fruiting vegetables, leafy greens and succulent-podded & 

succulent-shelled beans to ~0.7 lb a.i./A/season for basil and tuberous and corm vegetables. In 

contrast, for turf and ornamentals, the seasonal application rates are much higher at 3.0 and 3.12 

lb a.i./A, divided in 1 and 2 applications, respectively.

Table 1-2. Summary of use information for cyazofamid, based on the current and supplemental

label for Ranman®400SC Fungicide label (EPA Reg. No. 71512-3), and label for Cyazofamid 

400SC Turf and Ornamentals (EPA Reg. No. 71512-13). The IR-4 crops are shaded blue. Crops 

which were claimed in previous submissions are shaded yellow.

USE

SINGLE APP.

RATE

(lb. a.i./A)

NUMBER 

OF 

APPLICS.

SEASONAL 

APP. RATE 

(lb. a.i./A)

INTERVAL 

BETWEEN 

APPS. (days)

APPLICATION

METHOD

PHI

(days)

Basil 0.071-0.078 9 0.7 7

Foliar, sprinkler 

irrigation, can be 

applied on basil 

grown in greenhouses

0

Tuberous and Corm Vegetables, Crop 

Subgroup 1C (arracacha, arrowhoot, Chinese 

artichoke, Jerusalem artichoke, edible canna, 

bitter cassava, sweet cassava, chayote (root), 

chufa, casheen taro, ginger, leren, POTATO, 

tanier, turmeric, yam bean, true yam)

0.036-0.071 

(0.158 at 

planting; 0.071 

lay-by/ hilling)

10 0.71 7

Foliar, at plantingover the seed pieces, 

lay-by/ hilling

7

Fruiting Vegetables, Crop Group 8-10

[TOMATO, GROUND CHERRY, 

TOMATILLO, BELL PEPPER, COOKING 

PEPPER, PIMENTO, SWEET PEPPERS, 

EGGPLANT, PEPINO, OKRA, African 

eggplant, bush tomato, cocona, currant tomato, 

garden huckleberry, goji berry, groundberry, 

martynia, naranjilla, pea eggplant, non-bell 

pepper, roselle, scarlet eggplant, sunberry, tree 

tomato, cultivars, varieties and/or hybrids of 

these]

0.054-0.071 6 0.43 7

Foliar, to base of 

plant at transplanting

or in transplant water, 

sprinkler irrigation; 

for tomatoes grown 

in greenhouses as 

drench application

0

Leafy Greens, Crop Subgroup 4A

[amaranth (leafy amaranth, Chinese spinach, 

tampala), arugula (Roquette), chervil, edible 

leaved chrysanthemum, corn salad, garden cress, 

upland cress (yellow rocket, winter cress), 

dandelion, dock (sorrel), endive (escarole), 

lettuce (head & leaf), orach, parsley, garden 

purslane, winter purslane, radicchio (red 

chicory), SPINACH, New Zealand spinach, vine 

spinach (Malabar spinach, Indian spinach)]

0.071 6 0.43 7

Foliar, to the soil 

(post-plant 

application) as a band 

over the seed band or 

transplant, in 

transplant water, 

sprinkler irrigation

0
4

Table 1-2. Summary of use information for cyazofamid, based on the current and supplemental

label for Ranman®400SC Fungicide label (EPA Reg. No. 71512-3), and label for Cyazofamid 

400SC Turf and Ornamentals (EPA Reg. No. 71512-13). The IR-4 crops are shaded blue. Crops 

which were claimed in previous submissions are shaded yellow.

USE

SINGLE APP.

RATE

(lb. a.i./A)

NUMBER 

OF 

APPLICS.

SEASONAL 

APP. RATE 

(lb. a.i./A)

INTERVAL 

BETWEEN 

APPS. (days)

APPLICATION

METHOD

PHI

(days)

Succulent-Podded & SucculentShelled Beans [Cicer arietinum (chickpea, 

garbanzo bean), Lupinus spp. (including sweet 

lupine, white sweet lupine, white lupine and 

grain lupine), Phaseolus spp. (including kidney 

bean, lima bean, mung bean, navy bean, pinto 

bean, snap bean, waxbean), Vacia fava (broad 

bean, fava bean), Vigna spp. (including 

asparagus bean, blackeyed bean, cowpea)]

0.071 6 0.43 7

Foliar, sprinkler 

irrigation 0

Grapes (East of the Rocky Mountains) 0.054-0.071 6 0.43 10 G or A 30

Carrot 0.156 5 0.78 14

Pre-plant 

incorporated or 

surface application 

(broadcast or band) 

or overhead irrigation 

system

14

Cucurbit Vegetables (Crop Group 9) 

[includes cantaloupe, chayote, Chinese 

waxgourd, citron melon, cucumbers, gherkin, 

gourds, honeydew melon, Momordica spp., 

muskmelon, watermelon, pumpkin, squash, 

zucchini]

0.054-0.071 6 0.43 7

G, A, in transplant 

water, sprinkler 

irrigation

0

Turf [such as golf courses (including greens, 

tees and fairways), sod farms, seed farms, 

college and professional sports fields, and 

commercial lawns]

0.5-1.0 3 3.0 14 G N/A

Ornamentals [including conifers, grown in 

containers in greenhouses, outdoor nurseries and 

landscapes]

1.56 2 3.12 14

G, soil drench, soil 

surface spray, 

irrigation systems

N/A

Hops 0.054-0.071 6 0.43 7 G, A 3

Brassica (Cole) Leafy Vegetables & 

Turnip Greens (Crop Group 5) [includes 

broccoli, Chinese broccoli (gai lon), broccoli 

raab (rapini), Brussels sprouts, cabbage, Chinese

cabbage (bok choy), Chinese cabbage (napa), 

Chinese mustard (gai choy), cauliflower, cavalo 

broccolo, collards, kale, kohlrabi, mizuna, 

mustard greens, mustard spinach, rape greens, 

turnip greens]

Transplant soil 

drench 0.66, 

soil 

incorporation 

0.52, foliar 

0.072

1 soil + 5 

foliar 1.02 7

G, A, transplant soil 

drench, soil 

incorporation, foliar, 

sprinkler irrigation

0

Identification of specific data gaps and new environmental fate data:

In a previous DWA, it was pointed out that the environmental fate database for cyazofamid

consisted of mostly supplemental studies and that a degree of uncertainty surrounded estimates 

of drinking waters concentrations. New studies have been submitted to the Agency to clarify

these uncertainties: they included an aerobic soil metabolism, anaerobic aquatic metabolism, 

adsorption/desorption (batch equilibrium), bioconcentration in fish and solubility in saltwater. 

These studies were found to be either acceptable or supplemental. These new studies show a fate 

behavior of cyazofamid that is very similar than the studies that were previously reviewed. 
5

Thus, new modeling of parent cyazofamid and its metabolites of concern was not deemed 

necessary.

An update of the summary table of all the environmental fate data is provided in Table 1-3. 

MRID numbers for the new studies are redlined. Note that the half-lives and soil Kds and KOCs 

are substantially similar to those that were previously reported. Furthermore, metabolites 

reported in such studies are the same. There is a new bioconcentration in fish study; however, 

results derived from this study are not utilized to model EDWCs. Additional environmental fate 

characterization is given in Attachment A.

Table 1-3. Environmental fate data for cyazofamid. MRIDs for new fate data shown with Redline.

Parameter Value1 MRID

Aerobic soil 

metabolism 2

t1⁄2 = 6.1-6.4 days in a loamy sand soil from Ohio, Soil 1 (pH 6.5, %OC 0.66)

Major degradates: CCIM, CCIM-AM, and CTCA

454091-06

465377-05

t1⁄2 = 3.7-4.0 days in a Sandy loam soil from England, Soil 2 (pH 7.6, %OC= 1.2)

t1⁄2 = 4.3-4.4 days in a Sandy loam soil from England, Soil 3 (pH 6.9, %OC= 3.0)

t1⁄2 = 4.9-6.0 days in a Sandy soil from Germany, Soil 5 (pH 5.9, %OC= 0.63)

Major degradates: CCIM, CCIM-AM and CTCA

t1⁄2 = 4.3 d non-linear; 10.3 d linear in a Sandy loam soil from CA (pH 5.7, %OM= 0.8)

t1⁄2 = 3.0 d non-linear; 44.1 d linear in a Sandy clay loam from ND (pH~7.8, %OM= 5.8)

Major degradates: CCIM, CCIM-AM, CTCA and CCBA

454091-08

465377-06

477163-01

Anaerobic aquatic 

metabolism 2

t1⁄2 = 5.6-6.2 Days (total system): Milli-Q water/Sandy loam (~2:1) 

Major degradates (of the applied): CCIM (25%), CCIM-AM (17%); CTCA (22%)

t1⁄2 = 20.1 d linear; 10.5 d non-linear (total system): Creek water/Sandy loam from OH 

(~2:1) 

Major degradates (of the applied): CCIM (40.0%), CCIM-AM (19.8%); CTCA (62.8%)

454091-09

465377-11

467027-06

477163-02

Adsorption/

Desorption 

(Kd and 

Koc in L Kg-1)

[Imidazole-4-

14C]/[Benzene-U14C]:

Loamy sand (OH), Soil 1: Kd = 9.99/ 6.96 and Koc= 1,524/1,062

Sandy loam (UK), Soil 2: Kd = 43.31/87.00 and Koc= 1,444/2,900

Sandy loam (UK), Soil 3: Kd = 14.11/13.49 and Koc= 1,176/1,124

Sand (Germany), Soil 5: Kd = 5.14/ 4.14 and Koc= 815/ 657

Sandy loam (CA), Kd = NA/ 7.01 and Koc= NA/ 1,491

Sandy clay loam (ND) Kd = NA/ 39.5 and Koc= NA/ 1,171

454091-12

465377-13

477163-04

Bioconcentration 

in Fish

Invalid study

Low-dose samples BCF 161x whole fish. BCFK 123x for whole fish. DT50 of clearance 

1.0 days for whole fish. High dose samples BCF 170x for whole fish, based on total 

residues. BCFK 132x for whole fish. DT50 of clearance 0.69 days for whole fish. Species 

rainbow trout, temperature 120C, pH 8.1-8.3.

454091-38 

454091-39 

465377-24

477163-05

Saltwater Solubil. Cyazofamid 0.0476 mg/L; CCIM ≥115 mg/L; CCIM-AM 0.200 mg/L; CTCA 98.7 mg/L 477163-06

1

Soil 1: Loamy Sand, Ohio (pH 6.5, %OC= 0.66); Soil 2: Sandy loam, England (pH 7.6, %OC= 1.2); Soil 3: Sandy loam, England (pH 6.9, %OC= 3.0)

Soil 4: Loamy sand, England (pH 7.6, %OC= 1.1); Soil 5: Sandy soil, Germany (pH 5.9, %OC= 0.63).

2

Soil and aquatic systems range of half-lives are values for the two labels. It is noted that longer half-lives were observed for the 

aerobic/anaerobic aquatic systems in late intervals (a range of 19 to 30 days).

Attachments:

Attachment A. Electronic Copy of DWA Dated 03/24/09

Attachment B. Electronic Copy of DWA Dated 09/06/06
6

Attachment A. ELECTRONIC COPY OF DWA DATED 03/24/09

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE OF PREVENTION,

PESTICIDES AND TOXIC SUBSTANCES

PC Code No.: 085651

DP Barcode: D 356836

Date: March 24, 2009

MEMORANDUM

SUBJECT: Estimated Drinking Water Concentrations of Parent Cyazofamid and its 

Degradates CCIM, CCIM-AM and CTCA for Use in Human Health Risk 

Assessment (Use on Fruiting Vegetables, Crop Group 8 + Okra, and Grapes, East 

of the Rocky Mountains).

TO: Tony Kish, PM Team Reviewer

Janet Whitehurst, Risk Manager Reviewer

Cynthia Giles-Parker, Chief

Fungicide Branch

Registration Division (7505P)

AND: Nancy Tsaur, Chemist

Paula Deschamp, Chief

Registration Action Branch III

Health Effects Division (7509P)

FROM: José L. Meléndez, Chemist

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

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

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

This memorandum presents the Estimated Drinking Water Concentrations (EDWCs) for 

cyazofamid (CAS No. 120116-88-3), and for three of its major transformation products CCIM, 

CCIM-AM and CTCA, for use in the human health risk assessment (refer to appendix for the 

structures and nomenclature of these chemicals). The registrant seeks registration for the new 

uses of the chemical on fruiting vegetables + okra, and grapes (East of the Rocky Mountains).

Exposure to surface water is possible through surface water runoff, soil erosion and/ or off-target 

spray drift. The mobility of cyazofamid is moderate (Kd range 5.14-43.31 mL/g; KOC range 815-
7

1524 mL/gOC, moderately to slightly mobile); however, cyazofamid is labile under many

conditions (e.g., in metabolism studies and under aqueous photolysis conditions). However, it 

degrades to a number degradates, which appear to be persistent. For cyazofamid and for its 

major transformation products CCIM, CCIM-AM and CTCA (as per HED’s request), calculated 

using tier 2 aquatic linked models PRZM/ EXAMS (surface water, applications to turf and 

ornamentals) and the tier 1 aquatic model SCI-GROW (groundwater, applications to 

ornamentals), EDWCs were calculated. As summarized in Table 1, the surface water acute 

EDWC is 38.2 ppb. The surface water non-cancer chronic value is 133.5 ppb and the cancer 

chronic EDWC is 77.3 ppb. The value for ground water is 2.18 ppb, which is suitable for both 

acute and chronic exposures.

The above stated values represent upper-bound estimates of the parent and individual degradates’

concentrations that might be found in surface water and groundwater due to the use of 

cyazofamid on turf and ornamentals, as reported previously in DP Barcode 319466. It is noted 

that this is still a screening-level analysis. A more refined assessment could be performed. 

Should any questions arise, please, contact José L. Meléndez at melendez.jose@epa.gov.

Identification of specific data gaps:

The environmental fate database consists of mostly supplemental studies. A degree of 

uncertainty exists in estimates of drinking waters concentrations until new studies are submitted. 

EXECUTIVE SUMMARY 

Cyazofamid (CAS name: 4-Chloro-2-cyano-N,N-dimethyl-5-(4-methylphenyl)-1H-imidazole-1-

sulfonamide; IUPAC name: 4-chloro-2cyano-N,N-dimethyl-5-p-tolylimidazole-1-sulfonamide; 

CAS No. 120116-88-3: PC code 085651) is a cyanoimidazole selective fungicide. The 

pesticide’s mode of action is to target the fungi cytochrome bc1 (ubiquinone reductase) at Q1 

site. Cyazofamid is currently used on potatoes, cucurbits, turf, tomatoes and carrots and it is 

proposed to be used on fruiting vegetables + okra, and grapes (East of the Rocky Mountains) 

through an IR-4 tolerance petition.

This memorandum is a drinking waters assessment (DWA) that presents the EDWCs for parent 

cyazofamid, and the degradates CCIM, CCIM-AM and CTCA for use in an FQPA human health 

risk assessment. Cyazofamid fungicide and/or its degradates may reach both surface and 

groundwater under some conditions. The degradates’ EDWCs were modeled individually (as 

opposed to the use of the total residue approach). This was done because sufficient data were 

available on the degradates to model them individually (although some assumptions were made, 

see below). It is noted that DWAs were previously issued as follows:

Summary of Cyazofamid Drinking Water Exposure Assessments

Date DP Barcode Uses included

4/28/04 301099 Cucurbits, potatoes and tomatoes

9/6/06 319466 Turf and Ornamentals

3/5/08 342613 Carrots

This assessment 356839 Fruiting vegetables + okra, and grapes (East of the Rocky mountains)
8

This DWA builds largely upon the previous assessments. Additional runs were performed to 

cover the new crops; the highest EDWCs of all crops (past and present) were obtained for turf 

and ornamentals (surface waters) and ornamentals (ground water). The screening-level surface 

water and ground water EDWCs were obtained using the tier 2 linked aquatic models PRZM/

EXAMS and the tier 1 aquatic model SCI-GROW, respectively. EDWCs are summarized in 

Table 1 for three scenarios as follows:

 1

st scenario: the parent is applied at the maximum rate;

 2

nd scenario: the degradates CCIM and CCIM-AM (and CTCA) are applied at the parentmolar equivalent amounts, spreading the application rate through the degradates, 

according to the molecular ratios and the adjusted maximum percentages of the 

degradates observed in the environmental fate studies; and

 3

rd scenario: the terminal degradate, CTCA, is applied assuming application of 100% 

molar conversion of the parent to the degradate.

Based on the results presented in Table 1 below and a time-line of exposure, the surface water 

acute EDWC is 38.2 ppb (equal to the Parent “14.362 ppb” + CCIM “17.106 ppb” + CCIM-AM 

“6.699 ppb”). CTCA is not included in the surface water acute EDWC because it is not expected 

to be present in this time frame. The surface water non-cancer chronic is 133.5 ppb and the 

cancer chronic is 77.3 ppb (equal to the value for the terminal degradate, CTCA). For ground 

water, the EDWC is 2.18 ppb, which is suitable for acute and chronic exposures (equal to the 

value for the terminal degradate, CTCA).

Table 1. Maxima of surface and ground water EDWCs for cyazofamid and its relevant major 

degradates. Turf and ornamentals use pattern, previously reported in D319466 (dated 9/6/06).

Scenario Chemical

Surface water EDWCs (ppb) Ground 

water EDWC 

Acute (ppb)

Chronic “NonCancer”Chronic 

“Cancer”

1

st

 Scenario Cyazofamid 14.362 0.377 0.279 0.01180

2

nd

 Scenario

CCIM 17.106 12.094 10.600 0.00061

CCIM-AM 6.699 6.312 3.611 0.00270

3

rd

 Scenario CTCA 136.242 133.458 77.270 2.180

 EDWCs 38.2 133.5 77.3 2.18

The above stated values represent upper-bound estimates of the parent, individual degradates 

and/or terminal degradate concentrations that might be found in surface water and groundwater 

due to the use of cyazofamid on turf and ornamentals. EFED emphasizes that this is a screening 

level analysis, and should there be a need by HED, additional refinements can be made.

The EDWCs for cyazofamid were determined based on laboratory and fate data from mostly

supplemental studies. EFED suspects the possible poor extraction efficiency may have 

underestimated the half-lives of cyazofamid, which could result in lower model values for 

EDWCs. In this respect, it is noted that major identified degradates (CCIM, CCIM-AM and 

CTCA) may not constitute a significant part of the late accumulated un-characterized bound 
9

residue (due to the apparent adequate extraction of these degradates). A degree of uncertainty

exists in such estimates until new studies with proven extraction procedures are submitted.

PROBLEM FORMULATION

This is a drinking water assessment that uses modeling and monitoring data, if available, to 

estimate the ground water and surface water concentrations of pesticides in drinking water 

source water (pre-treatment) resulting from pesticide use on sites that are highly vulnerable.

Background

This assessment addresses exposure to parent cyazofamid and its degradation products CCIM, 

CCIM-AM and CTCA. As indicated above, three DWAs have been conducted for cyazofamid. 

Final EDWCs were presented for the use on turf and ornamentals, which were covered in one of 

the previous assessments.

In the DWA for turf and ornamentals, the highest acute EDWCs were observed for the use on 

turf for the parent and CCIM, and ornamentals for CCIM-AM. The highest chronic EDWCs 

were observed for the use on ornamentals. The application rate for ornamentals was 1.56 lb 

a.i./A (two applications), and for turf 1.02 lb a.i./A (three applications). It should be noted that 

there are no substantial changes in the DWA methodology since the last assessment. There are 

no new data in the fate database. Only the new crops were modeled.

Cyazofamid is characterized by a high molecular weight (324.79 g/mole), has a relatively low 

solubility (0.107 ppm @ pH 7) and a low vapor pressure and Henry’s Law Constant (<1.0 x10-7

mmHg, and <4.0x10-7atm*m

3

/mole, respectively). Therefore, cyazofamid is not expected to 

partition substantially into the air from water or from dry or wet soil surfaces. Available data 

suggest that cyazofamid has the potential to be bio-concentrated by aquatic organisms such as 

fish (KO/W > 1000), but EFED does not have a valid bio-accumulation in fish study at this time. 

Available environmental fate studies suggest that cyazofamid is not very mobile, and that it 

quickly degrades into various products, depending on the environmental conditions. Among the 

three major degradates for cyazofamid (CCIM, CCIM-AM and CTCA), the two terminal 

degradates are CCIM and CTCA. CCIM is the major one in bodies of water with low biological 

activity because it is the result of abiotic hydrolysis of the parent. CTCA is expected to be the 

major terminal degradate in biologically active soils and in water/sediment systems. Both CCIM 

and CTCA are stable to abiotic hydrolysis and susceptible to leaching but only CCIM is 

susceptible to biodegradation. Cyazofamid could potentially reach surface water via spray drift 

or runoff under certain environmental conditions but the potential for it to reach ground water is 

low. CCIM and CTCA could potentially be the terminal degradates in surface water bodies 

affected by spray drift and/ or runoff depending on the level of biological activity. However, 

only CTCA has a high potential to contaminate groundwater due to its high persistence and 

mobility.
10

Use Characterization

Cyazofamid is currently used on carrots, cucurbit vegetables, potatoes and tomatoes. In addition, 

it is used on turf and ornamental plants, including container grown plants and field grown (bed) 

plants.

Table 2. Summary of new use information for cyazofamid, based on the proposed 

Ranman 400SC Fungicide label (EPA Reg. No. 71512-3).

USE

SINGLE APP. 

RATE 

(lbs. a.i./A)

NUMBER 

OF APPS.

SEASONAL 

APP. RATE 

(lbs. a.i./A)

INTERVAL 

BETWEEN 

APPS. (days)

APP.

METHOD PHI (days)

Fruiting Vegetables (Crop 

Group 8) and Okra [includes 

tomato, ground cherry, tomatillo, 

bell pepper, chili pepper, cooking 

pepper, pimento, sweet peppers, 

eggplant and pepino]

0.054-0.0782 6 (@ 

0.071) 0.426 7

Sprinkler 

Irrigation1 0

Grapes (East of the Rocky 

Mountains) 0.054-0.071 6

3

0.426310 G or A 30

1

Includes center pivot, motorized lateral move, traveling gun, solid set or portable (wheel move, side roll, end low, 

or hand move) irrigation systems.

2

The use at 0.078 lb a.i. is for greenhouse transplant production, for control of Pythium spp.

3

The registrant indicated that the maximum rate is 6x0.071 lb a.i./A or 0.426 lb a.i./A/season.

The label indicates that the product “may be applied with all types of spray equipment normally

used for ground and aerial applications.” The label further specifies that a maximum of three 

applications in a series are allowed, and that they should be alternated with a fungicide of 

different mode of action, to manage/ prevent resistance. Aerial applications to grapes are 

allowed. The label does not have a requirement of an established buffer strip to protect bodies of 

water.

For cucurbits vegetables, the label was amended. The new label now allows the use of 

cyazofamid for greenhouse transplant production at 0.078 lb a.i./A to control Pythium spp. 

However, for cucurbits, the most conservative scenario still is 6 applications at 0.071 lb a.i./A

(same one previously assessed). In addition to the above mentioned label, EFED evaluated the 

label amendment for Cyazofamid 400SC Turf and Ornamentals Fungicide (EPA Reg. No. 

71512-13) to include applications to residential lawns by professionals. The major change is the 

inclusion of residential uses for turf. There are no changes in the maximum application rates for 

turf or ornamentals; therefore, these changes were not assessed hereby. Both products are 

flowable suspension concentrates (SC). Both products contain 34.5% active ingredient or 3.33 lb 

a.i./gallon.
11

Based on the crops listed for cyazofamid, use is expected all throughout the USA. There is a 

single geographical label restriction on the use on grapes, that it may be used only East of the 

Rocky Mountains (consequently, it may not be used on the high use area on grapes in the state of 

California). At this time, there is no readily available typical use or usage information for 

cyazofamid.

Conceptual Model 

The conceptual model is a written description and visual representation of potential routes of offsite movement of the pesticide or degradates of concern into surface or ground water that may be 

a source of drinking water. The conceptual model describes the approach that will be used in the 

analysis phase and includes two components: the risk hypothesis and the conceptual site model 

for surface and ground water.

For cyazofamid, the following drinking water hypothesis is being employed for this assessment:

Cyazofamid use in accordance with the label, results in potential contamination of 

surface water resources; it does not result in contamination of ground waters because it 

is relatively labile. Degradates of concern of cyazofamid, CCIM, CCIM-AM and CTCA, 

result in substantial contamination of surface and ground water resources because they 

are formed in large quantities and/or persist.

The conceptual site model is a generic graphic depiction of the risk hypothesis. Through a 

preliminary iterative process of examining available data, the conceptual model (i.e., the drinking 

water hypothesis) is refined to reflect the likely exposure pathways that are most relevant and 

applicable to this assessment (refer to the following figure).
12

Cyazofamid is applied to the field (on numerous crops). It appears that crop uptake is 

unlikely or minimal because the KOC for the chemical is moderately high (ranged from 657-

2900). In addition, the chemical shows a relatively low solubility (0.107 ppm) and a high 

octanol/ water partition coefficient (KOW = 1585). Cyazofamid is not expected to move

substantially on/in the soils horizontally because it is not very persistent. On the other hand, 

spray drift is an important factor in the contamination of nearby surface waters when 

cyazofamid is applied to the field since it may be applied by aerial or ground methods. Since 

the field may be kept irrigated, large runoff events and events accompanied with erosion may

be a factor in horizontal movement for cyazofamid’s degradates CCIM and CCIM-AM, 

resulting in acute exposure. Since cyazofamid is a labile compound, it may not be available 

for long periods of time in the field; on the other hand, the degradate CTCA appears to be 

more persistent. CTCA is expected to be present in surface waters on a chronic basis. 

Vertical movement to subsurfaces is expected to be an important component for CTCA, 

particularly after repeated applications per year and year to year. Volatilization is expected 

to be a minor route of dissipation for the active ingredient (Henry’s Law Constant <4.0x10-7

atm*m

3

/mol).

ANALYSIS

Fate and Transport Characterization:

A summary of physicochemical properties of cyazofamid is shown in Table 3. The chemical is a 

relatively insoluble compound in acidic, neutral and alkaline conditions. The low vapor pressure 

and Henry’s Law constant of cyazofamid suggest partitioning into the air from water and/or dry

or wet soil surfaces will not be an important route of its dissipation in the environment. 

Cyazofamid has a KOW >1,000 suggesting that it will potentially be bio-concentrated by aquatic 

organisms such as fish. However, at this time, EFED does not have a valid bioaccumulation in 

fish study.
13

Table 3. Nomenclature and physicochemical properties of cyazofamid

Parameter Value MRID1

Chemical Classification cyanoimidazole

Molecular Formula C13H13ClN4O2S

Chemical Name (IUPAC) 454090-38

4-chloro-2cyano-N,N-dimethyl-5-p-tolylimidazole-1-

sulfonamide

Chemical Name (CAS)

4-Chloro-2-cyano-N,N-dimethyl-5-(4-methylphenyl)-1Himidazole-1-sulfonamideCyazofamid 

data sheet

CAS Number 120116-88-3

454090-38

Pesticide Classification Fungicide

Molecular Weight 324.79

Physical State Crystalline solid

Water Solubility (ppm) 0.121 @ pH 5, 0.107 @ pH 7, 0.109 @ pH 9

Vapor pressure (25oC) <1.33 x10-5Pa or <9.9810-8 mmHg or <1.32x10-10 atm.

EPA Fact 

sheet

Henry's Law Constant <4.0x10-7atm. m3 mole-1 Calculated

Octanol/Water Partition, KOW 1,585 (log KOW 3.2 @ 25°C) 454090-38

1

Study reference is an MRID number.

Cyazofamid and degradates fate and transport properties are based on previously submitted 

studies and reports (EPA Risk Assessments dated 2004, 2006 and 2008). Although, EFED 

requested additional studies, no new studies have been submitted. Cyazofamid’s environmental 

fate data are summarized in Table 4.

Table 4. Summary of environmental fate data for cyazofamid

Parameter Value1 MRID

Hydrolysis

t1⁄2 ~ 11.9 days @ 25oC, pH 4

t1⁄2 ~12.9 days @ 25oC, pH 5

t1⁄2 ~ 11.9 days @ 25oC, pH 7

t1⁄2 ~10.8 days @ 25oC, pH 9

t1⁄2 ~ 13.4, 12.4, 11.2, 9.3 hrs @ 50 o C, pH’s 4, 5, 7, 9, respectively

Major degradates (of the recovered): CCIM (74-83%) and CCIM-AM (9-10% only at 

pH 9)

454090-39

465377-01

467027-01

Aqueous 

photolysis

at pH 5

t1⁄2 ~ 30 Minutes

Major degradates: CCTS (37.9% at 0.13 day), CCIM (39.6% at 0.25 and 2 days), HTID 

(18.5% at 21 days), and CDTS (9.6% at 36 days). The degradate p-Toluamide (12.1% at 

36 days) was identified only in the [benzene14C] cyazofamid.

454091-02

465377-03

467027-03

Photolysis on soil

t1⁄2 ~ 47 days

Major degradates: None.

Minor degradates: CCIM (6%), CCBA (2%), CTCA (1%), and CCIM-AM (<1%). 

454091-03

465377-04

467027-04

Aerobic soil 

metabolism 2

t1⁄2 = 6.1-6.4 days in a loamy sand soil from Ohio, Soil 1 (pH 6.5, %OC 0.66)

Major degradates: CCIM, CCIM-AM, and CTCA

454091-06

465377-05
14

Table 4. Summary of environmental fate data for cyazofamid

Parameter Value1 MRID

t1⁄2 = 3.7-4.0 days in a Sandy loam soil from England, Soil 2 (pH 7.6, %OC= 1.2)

t1⁄2 = 4.3-4.4 days in a Sandy loam soil from England, Soil 3 (pH 6.9, %OC= 3.0)

t1⁄2 = 4.9-6.0 days in a Sandy soil from Germany, Soil 5 (pH 5.9, %OC= 0.63)

Major degradates: CCIM, CCIM-AM and CTCA

454091-08

465377-06

Aerobic aquatic 

metabolism 2

t1⁄2 = 14.7- 18.0 days (total system): River water/Sandy loam (~3:1) 

t1⁄2 = 9.5- 10.9 days (total system): Creek water/Sandy loam (~3:1)

Major degradates: CCIM (up to 47%), CTCA (up to 31%), and CCIM-AM (up to 11%)

454091-10

465377-12

467027-07

Anaerobic aquatic 

metabolism 2

t1⁄2 = 5.6-6.2 Days (total system): Milli-Q water/Sandy loam (~2:1) 

Major degradates (of the applied): CCIM (25%), CCIM-AM (17%); CTCA (22%)

454091-09

465377-11

467027-06

Adsorption/

Desorption 

(Kd and 

Koc in L Kg-1)

[Imidazole-4-

14C]/[Benzene-U14C]:

Loamy sand (Ohio), Soil 1: Kd = 9.99/ 6.96 and Koc= 1,524/1,062

Sandy loam (UK), Soil 2: Kd = 43.31/87.00 and Koc= 1,444/2,900

Sandy loam (UK), Soil 3: Kd = 14.11/13.49 and Koc= 1,176/1,124

Sand (Germany), Soil 5: Kd = 5.14/ 4.14 and Koc= 815/ 657

454091-12

465377-13

Mobility in Soils: 

Column Un-aged 

Leaching (4 soils)

> 98% of the applied radioactivity remained on the top 10 cm with very limited leaching. 

Observed rate and pattern of degradation were similar to aerobic soil (Major degradates: 

CCIM, CCIM-AM). Leachate constituted <0.3% of the applied radioactivity.

454091-13

465377-16

Mobility in Soils: 

Aged Leaching 

(one soil)

>95% of the radioactivity remained on the top 10cm with very limited leaching. Observed 

rate and pattern of degradation were similar to aerobic soil (Major degradates: CCIM, 

CCIM-AM, and minor degradate CTCA). Leachate constituted nearly 1% of the applied 

radioactivity and was dominated by the degradate CTCA only. In comparison with 

unaged soils, radioactivity profile indicated aging may have caused increased mobility

454091-11

465377-15

Accumulation in 

Fish Invalid study

454091-38 

454091-39 

465377-24

1

Soil 1: Loamy Sand, Ohio (pH 6.5, %OC= 0.66); Soil 2: Sandy loam, England (pH 7.6, %OC= 1.2); Soil 3: Sandy loam, England (pH 6.9, %OC= 3.0)

Soil 4: Loamy sand, England (pH 7.6, %OC= 1.1); Soil 5: Sandy soil, Germany (pH 5.9, %OC= 0.63).

2

Soil and aquatic systems range of half-lives are values for the two labels. It is noted that longer half-lives were observed for the 

aerobic/anaerobic aquatic systems in late intervals (a range of 19 to 30 days).

Available environmental fate studies suggest cyazofamid is not very mobile and degrades 

relatively rapidly into various products, according to the prevalent environmental conditions. 

Among the three major degradates for cyazofamid, relevant to this assessment (CCIM, CCIMAM and CTCA), the two terminal degradates are CCIM and CTCA. Of them, CCIM is a major 

hydrolysate. It is expected to be the major terminal degradate in bodies of water with low 

biological activity. In contrast, CTCA is expected to be the major terminal degradate in 

biologically active soils and water/sediment systems. Both CCIM and CTCA are stable to 

abiotic hydrolysis and susceptible to leaching but only CCIM is highly susceptible to 

biodegradation. Given these fate characteristics, cyazofamid could potentially reach surface 

water via spray drift, or runoff under certain environmental conditions, but the potential for it to 

reach ground water is low. CCIM and/or CTCA could potentially be the terminal degradates in 

surface water bodies affected by spray drift and/or runoff depending on the level of biological 

activity. However, only CTCA has a high potential to contaminate groundwater due to its high 

persistence and mobility.

Based on the referenced data, the main process involved in cyzofamid fate in aqueous systems is 

direct photolysis followed by hydrolysis. Its fate in the soil system appears to be controlled by

biotic degradation as well as its strong affinity for adsorption to the soil. Mobility of cyazofamid 
15

in natural environments is expected to be limited because of its strong affinity to adsorption. 

Available fate and transport data on cyazofamid major degradates CCIM, CCIM-AM and CTCA, 

are presented in Table 5.

Table 5. Environmental fate data summary for the major and relevant degradates of cyazofamid.

Parameter 1

Value (t1⁄2 for [phenyl-U14C] - t1⁄2 for [imidazole-4-

14C]

CCIM CCIM-AM CTCA MRID ()

Hydrolysis All three were relatively stable @ 50oC for 5 days in pHs 4, 7, and 9.

454091-01

465377-02

467027-02

Aerobic soil 

metabolism 3

Soil 3 t1⁄2 = 1.92

- 1.3 days t1⁄2 = 6.3 - 6.6 days

t1⁄2 >120 days

(relatively stable) in 

all three soils 

CCIM

454091-07

465377-07

465524-01

CCIM-AM

454091-04

465377-09

467027-05

CTCA

454091-05

465377-10

Soil 4 t1⁄2 = 1.3 - 0.9 days t1⁄2 = 10.0 - 6.6 days

Soil 5 t1⁄2 = 2.9 - 2.6 days t1⁄2 = 20.2 - 12.3 days

Major 

degradates

CCIM-AM, CTCA, 

CCBA-AM.

CTCA (max. 49.5-

57.4% of the applied) None identified

Adsorption/ 

Desorption 

(Kd and Koc

in L Kg-1)

Using:

[BenzeneU14C]

Soil 1

Kd= 3.91

Koc= 594

Kd= 22.43

Koc= 3,398

Kd= 8.96

Koc= 1,357

454091-14

465377-14

Soil 2

Kd= 5.70

Koc= 475

Kd= 23.30

Koc= 1,941

Kd= 9.80

Koc= 816

Soil 3

Kd= 23.57

Koc= 786

Kd= 62.47

Koc= 2,082

Kd= 17.16

Koc= 572

Soil 5

Kd= 7.3

Koc= 1,158

Kd= 13.64

Koc= 2,165

Kd= 3.77

Koc= 599

1

Soil 1: Loamy Sand, Ohio (pH 6.5, %OC= 0.66); Soil 2: Sandy loam, England (pH 7.6, %OC= 1.2); Soil 3: Sandy loam, 

England (pH 6.9, %OC= 3.0); Soil 4: Loamy sand, England (pH 7.6, %OC= 1.1); and Soil 5: Sandy soil, Germany (pH 5.9, 

%OC= 0.63).

2 New submittals changed this value from 1.4 days to 1.9 days; this slight change may not significantly impact the values used 

in modeling.

3 Range of half-lives are values for the two labels. It is noted that longer half-lives were observed at later in the experiments 

(a range of 2-7 days for CCIM and 14-28 days in the first two soils and >112 days for the third soil for CCIM-AM.

Data on hydrolysis suggest that the three degradates are stable to this abiotic process. Various 

conclusions are derived from the data on aerobic soil metabolism and mobility. The first major 

degradate, CCIM, appears to be susceptible to leaching but is short-lived. CCIM-AM is similar 

to its parent in its low persistence/mobility. Finally, the degradate CTCA appears to be 

susceptible to leaching with high persistence. The major terminal-degradate in biologically active 

soil and aquatic environments is expected to be CTCA because of the apparent transformation of 

CCIM to CCIM-AM and finally into the persistent CTCA. Cyazofamid reaching surface water 

is expected to be highly affected by hydrolysis, which transforms it into CCIM, which is stable to 

abiotic hydrolysis. Therefore, CCIM is expected to be the major terminal degradate in bodies of 

surface water with low biological activity. Details on fate and transport studies including the 

transformation profile are included in the three previously completed EFED chapters (EPA 2004, 
16

2006 and 2008). 

A summary of previously submitted field studies is shown in Table 6. 

Table 6. Summary of the terrestrial field dissipation study on cyazofamid

Location (MRID) Half-life1

Soil Dissipation of Cyazofamid and its Degradation Products

Grant County, 

WA

454091-16 (O)

465377-17 (R)

465524-02 (A) t1⁄2 = 1.5 days

Loamy sand

pH: 6.5

OM: 0.60%

Cyazofamid: was not detected below 0-15 cm.

Degradation Products: CCIM-AM and CTCA (detected through 

540 days).

CTCA was detected 8 times in the 15-30 cm soil layer throughout the 

540-day experiment.

Wayne County, 

NY

454091-17 (O)

465377-20 (R)

465524-03 (A) t1⁄2 =8.5 days

Sandy loam

pH: 6.1

OM: 3.33%

Cyazofamid: was not detected below 0-15 cm.

Degradation Products: CCIM-AM (detected through 28 days), and 

CCBA (detected sporadically at 0.03-0.01 ppm); CCIM and CTCA 

detected at 0.01-0.02 ppm through the 540-day study.

Degradates were not generally detected below 0-15 cm with the 

exception of CTCA which was sporadically detected in the 15-30 cm 

layer. 

Montezuma, GA

456385-12 (O)

465377-23 (R)

467842-01 (A) t1⁄2 = 2.0 days

Loam

pH: 6.2

OM: 0.55%

Cyazofamid: was not detected below 15 cm.

Degradation Products: CCIM, CCIM-AM and CTCA (detected 

through 540 days).

Only CCIM-AM was sporadically detected in the 15-30 cm layer.

Watsonville, CA

456385-13 (O)

465377-22 (R)

467842-02 (A) t1⁄2 = 15 days

loam

pH: 6.5

OM: 2.38%

Cyazofamid: was detected only once below 15 cm.

Degradation Products: CCIM-AM and CTCA were detected 

through 582 days with maximum concentrations reaching >10%, 

CCBA (detected through 582 days), and CTCA detected at the end 

of the study period.

Degradates were not detected below 0-15 cm, except of CCIM-AM 

which was sporadically detected.

Pikeville, NC

465871-01

t1⁄2 days:

Grass: 7

Thatch: 29-32 

Soil: 15-120

Sandy loam

pH: 5.7

OM: 2.2%

Cyazofamid: was detected only once in the 7.5-15 cm soil layer.

Degradation Products: CCIM, CTCA, CCIM-AM, and CCBA 

were all detected in minor amounts (<10%) in the three layers while 

only CCIM-AM was detected at >10% of the total applied parent in 

the thatch layer only.

Ashland, VA

465711-02

t1⁄2 days:

Grass: 3

Thatch: 09-26 

Soil: 10-25

Sandy loam

pH: 6.8

OM: 1.1%

Cyazofamid: was detected only once in the 7.5-15 cm soil layer.

Degradation Products: CCIM, CTCA, CCIM-AM, and CCBA 

were all detected in minor amounts in grass and thatch layers while 

only CTCA was detected in minor amounts in the soil layer.

1

t1⁄2 = first order half-life; DT50= Dissipation time of 50% of the compound.

The major uncertainties in the environmental fate database are related to the fact that the halflives were obtained from supplemental aerobic soil, and aerobic and anaerobic aquatic 

metabolism studies. It is suspected that poor extraction may have caused an underestimation of 

the half-lives of cyazofamid and degradates. On the other hand, the major identified degradates 

(CCIM, CCIM-AM and CTCA) may not be a significant portion of the late accumulated uncharacterized bound residues. The extraction of these degradates appeared to be adequate; 

however, a degree of uncertainty exists in the half-life estimates until new studies are submitted 

with proven extraction procedures. No data were submitted by the registrant to suggest that 

reasonable attempts were made to extract or analyze significant soil or sediment bound 
17

radioactivity.

Drinking Water Exposure Modeling

In order to model the new crops, representative scenarios were chosen: CA tomato, FL peppers 

and PA tomato, to represent fruiting vegetables and okra; and NY grapes, to represent grapes -

East of the Rocky Mountains. The maximum application rate allowed by the label was utilized.

 Model Selection:

Models

SCI-GROW (Screening Concentration in Ground Water v.2.3) (SG23.exe, July 29, 2003)

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

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

model to groundwater concentrations with the Relative Index of Leaching Potential 

(RILP) as the independent variable. Groundwater concentrations were taken from 90-

day average high concentrations from Prospective Ground Water studies; the RILP is a 

function of aerobic soil metabolism and the soil-water partition coefficient. The output of 

SCI-GROW represents the concentrations that might be expected in shallow unconfined 

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

to pesticide contamination likely to serve as a drinking water source. (Ref. 8).

For agricultural uses, exposure concentrations for surface drinking waters assessments 

were estimated based on EFED’s Tier 2 aquatic model PRZM/ EXAMS. A graphical 

user interface (PE5 v. 5.0, November 15, 2006), developed by the EPA 

<http://www.epa.gov/oppefed1/models/water>, was used to facilitate inputting chemical 

and use specific parameters into the appropriate PRZM input files (inp) and EXAMS 

chemical files. The Pesticide Root Zone Model (PRZM v. 3.12.2, May 12, 2005) field or 

orchard crop scenario is the basic file which describes the local or regional 

climatological information, soil hydrology, soil characteristics, crop characteristics, and 

the pesticide properties necessary to determine pesticide loadings to surface (or ground)

water. This basic file constitutes the first part of the “exposure scenario.” It simulates 

the processes in the agricultural field, such as runoff and erosion, on a daily time step. 

The runoff and erosion flux output data from PRZM are used as chemical loadings to the 

Exposure Analysis Modeling System (EXAMS v. 2.98.04.06, April 25, 2005), which 

simulates surface water, in order to predict the EDWCs. EDWCs were determined using 

a reservoir scenario which describes a vulnerable surface drinking waters scenario for 

the EXAMS component of the modeling exercise.

 Scenario Selection.

As indicated earlier, representative scenarios were chosen. The crop scenarios, selected to 

represent fruiting vegetables and okra, were CA tomatoes, FL peppers and PA tomatoes (selected 

to represent different regions of the USA). The crop scenario chosen to represent grapes - East 

of the Rocky Mountains, is NY grapes (this is the single standard grape scenario available in the 
18

East of the USA). The application dates were selected according to the met file, to represent 

typical use of a fungicide on the crops listed above.

 Approach to calculation of EDWCs for cyazofamid and its degradates

Cyazofamid is a relatively new fungicide and no surface water monitoring data are available. 

For this reason, the Agency based this report on simulated screening values using modeling. The 

screening level surface water and ground water estimates are calculated using tier 2 linked 

PRZM/EXAMS models and the tier 1 SCI-GROW model, respectively. It is noted that: 

 EDWCs for cyazofamid and its degradates were generated from the models in which the KOC and 

aerobic soil half-life values used were obtained from supplemental studies; 

 Solubility of the degradates were considered to be the same as parent (0.107 ppm); 

 Direct photolysis half-life for the degradate CCIM was estimated from its formation and decline 

curve in the aqueous photolysis study conducted on the parent (a half-life of 31.52 days); 

 The degradates CCIM-AM and CTCA were considered to be stable to direct photolysis in water 

as they were not identified in the parent aqueous photolysis study, and therefore, half-lives could 

not be calculated; and 

 The initial residue levels for degradates used in the models were based on molecular ratios; 

assuming time zero 100% conversion of parent to a mixture of degradates based on weight 

adjusted maximums in fate studies. EFED believes that this assumption is reasonable and 

conservative. The calculated initial residue levels are presented in Table 7.

Table 7. Calculated application rates used in modeling of scenarios 1 (parent only), 2 (mix of 

degradates), and 3 (CTCA only, terminal degradate)

Chemical

Molecular 

Weight *

Molecular 

Ratio

Determined Maximum (% Parent Equivalent)

Application Rate**

(lb a.i./A)

Value Adjusted Value Fate Study Used Fruit. Veg. Grapes

Parent 324.79 1 100% 100% Assumed 0.071 0.071

CCIM 217.66 0.6702 83% 63% Hydrolysis 0.0300 0.0300

CCIM-AM 235.67 0.7256 17% 13% Anaerobic Aquatic 0.00670 0.00670

CTCA 236.66 0.7287 31% 24% Aerobic Aquatic 0.0124 0.0124

Total 131% 100%

CTCA 236.66 0.7287 100% 100% Assumed 0.0517 0.0517

* Molecular weights for degradates of cyazofamid were calculated by deduction/ addition of elements, when 

compared to the parent structure.

** Rate for each degradate = Parent Rate x Molecular Ratio x adjusted maximum found in fate studies; for example 

the rate for CCIM application on fruiting vegetables = 0.071 x 0.6702 x 63% = 0.0300 lb a.i/A.

Based on the procedure outlined above, the application rates (in kg a.i./A, the units used in 

PRZM/ EXAMS) used for the different runs are included, along with other modeling parameters, 

in Table 8. 
19

Table 8. Modeling parameters for cyazofamid and degradates

Scenario

Modeled 

Chemical

Max. Single Rate (kg a.i./ha)* Other parameters

Fruit. Veg. Grapes

Fruiting Vegetables

Number of applications: 6

Minimum interval: 7-day**

Scenario (application date): 

CA (11-03) and PA tomato 

(26-04); FL pepper (11-09)

Application Efficiency: 0.99

Drift: 0.01

Intervals: 7, 7, 21, 7, 7 days

Grapes

Number of applications: 6

Minimum interval: 10-day**

Scenario (application date): 

NY grape (05-05)

Application Efficiency: 0.95

Drift: 0.05

Intervals: 10, 10, 30, 10, 10 

days

First Parent 0.0796 0.0796

Second

CCIM 0.0336 0.0336

CCIM-AM 0.0075 0.0075

CTCA 0.0139 0.0139

Third CTCA 0.0579 0.0579

* By multiplying label rates in lb/A by the conversion factor 1.1208; for example for fruiting vegetables, parent: 

Application Rate = 0.071 x 1.1208 = 0.0796 kg/ha.

**The label instructs not to make more than two or three consecutive applications of the product; instead, follow with 

at least two or three applications of a fungicide with a different mode of action. Intervals are as indicated.

Fate and transport input parameters are summarized in Table 9.

Table 9. PRZM/EXAMS input parameters for modeling surface water’s EDWCs of cyazofamid

Input Parameter Chemical Value1Reference

Molecular Weight (gram 

mole -1)

Parent 324.79

MRID 454090-38

CCIM 217.66

CCIM-AM 235.67

CTCA 236.66

Vapor Pressure (mmHg) All 1.0x10-7 EPA Factsheet

Henry’s Law Constant 

(atm-m

3 mole-1

) All 4.0x10-7 Calculated

Aerobic Soil 

Metabolism Half-life 

(days)

Parent 5.5

The 90th percentile t1⁄2 from eight values for the parent and six 

values for each degradate (MRIDs 454091 06/08/07/04/05).

CCIM 2.22

CCIM-AM 13.58

CTCA Stable

Water column Half-life 

(days)

(Aerobic Aquatic 

Metabolism half-life)

Parent 16.4

The 90th percentile t1⁄2 from four values for the parent (MRID 

454091-10). For the degradates, twice the aerobic soil 

metabolism input since the degradates are stable to hydrolysis, as 

per guidance (US EPA, 2002)

CCIM 4.44

CCIM-AM 27.16

CTCA Stable

Benthic sediment Half- Parent 17.7 One half-life value; 3x5.9=17.7 (MRID 454091-09)
20

Table 9. PRZM/EXAMS input parameters for modeling surface water’s EDWCs of cyazofamid

Input Parameter Chemical Value1Reference

life (days) 

(Anaerobic Aquatic 

Metabolism half-life) Degradates Stable No anaerobic aquatic metabolism data

Application Rate (Kg 

a.i./ha) All; Refer to Table 8

Application Number 

(Method of application) All; Refer to Table 8 Product Label

Application Interval All; Refer to Table 8 Product Label

IPSCND (disposition of 

pesticide remaining on 

foliage after harvest) All 1

Pesticide remaining on foliage is converted to surface application 

to the top soil layer

UPTKF = PLVKRT = 

PLDKRT All 0 As per Guidance for Selecting Input Parameters.

1

FEXTRC All 0.5 As per Guidance for Selecting Input Parameters.

1

Depth of Incorporation 

(cm)

Parent 0.0

CAM=2/ linear foliar based on crop canopy (label); parent is 

applied by ground or aerial methods

Degradates 5.08

CAM=4/soil application (Product Label); degradate is expected 

to form, from parent in the top soil

Spray Drift (fraction)

Parent and 

Degradates

0.064 for fruiting vegetables and 0.16 for grapes; degradates are expected to 

form in the surface water

Application Efficiency

(fraction)

Parent and 

Degradates 0.99 for fruiting vegetables and 0.95 for grapes

Solubility (ppm)

Parent and 

Degradates 1.07 10X the solubility as per guidance MRID 454090-38

KOC (L Kg-1)

Parent 1,338

Parent: Average of eight values (MRID 454091-12). 

Degradates: Average of four values for each of degradates 

(MRID 454091-14). 

KOC model was determined to be appropriate.

CCIM 753

CCIM-AM 2,397

CTCA 836

Hydrolysis Half-life @ 

pH 7 (days)

Parent 11.9 Maximum value at pH 7 (MRID 454090-39) 

Degradates Stable MRID 454091-01

Aqueous Photolysis 

Half-life (days)

Parent 0.02

CCIM 31.5 Maximum dark control corrected value (MRID 454091-02)

Other 

degradates Stable No data

1 Parameters are selected as per Guidance for Selecting Input Parameters in Modeling the Environmental Fate and 

Transport of Pesticides; Version II, February 28, 2002.

Results of PRZM/EXAMS modeling are summarized in Table 10, noting that an 87% was used 

for Percent Crop Area (PCA). The value of 87% is the national default for all other crops.
21

Table 10. PRZM/EXAMS results of this assessment (EDWCs in ppb)

Crop/Scenario PCA (%) Chemical Peak Yearly All Years

CA Tomato

1

st 87% Parent 0.568 0.0184 0.0137

2

nd

87% CCIM 0.183 0.0171 0.0144

87% CCIM-AM 0.0689 0.0172 0.0148

3

rd 87% CTCA 1.90 1.35 1.16

FL pepper

1

st 87% Parent 3.50 0.0662 0.0407

2

nd

87% CCIM 0.541 0.0180 0.0122

87% CCIM-AM 0.191 0.0227 0.0166

3

rd 87% CTCA 7.93 1.37 0.992

PA tomato

1

st 87% Parent 1.04 0.0501 0.0245

2

nd

87% CCIM 0.189 0.0164 0.0130

87% CCIM-AM 0.117 0.0318 0.0211

3

rd 87% CTCA 3.80 1.95 1.49

NY grape

1

st 87% Parent 1.32 0.0552 0.0442

2

nd

87% CCIM 0.326 0.0385 0.0325

87% CCIM-AM 0.177 0.0703 0.0585

3

rd 87% CTCA 4.81 3.41 2.67

Maxima

*Parent + CCIM + CCIM-AM 4.23*

**CTCA only 3.41** 2.67**

For ground water, SCI-GROW program, a high exposure tier one model, was used to arrive at 

the Estimated Drinking Water Concentration (EDWC) for this chemical and its degradates from 

ground water sources. Modeling input and output values are summarized in Tables 11 and 12, 

noting that the rates are the ones for the highest exposure (ornamentals). In addition, scenarios 1 

and 2 are for information only, since the parent and the degradates CCIM and CCIM-AM are not 

likely to be observed in ground waters.

Table 11. Input data for SCI-GROW modeling for EDWCs from ground water for cyazofamid/ degradates

Parameter Value* Reference (MRID Number)

Crop/ Seasonal No. of Applications

Soil Applied to 

Ornamentals/2 High Exposure (maximum rate/number); Product label

Label 

Application 

Rate (lb 

a.i./acre)

1

st Scenario: Parent 1.56 Product label (lb a.i/A)

2

nd Scenario: CCIM 0.659

Calculated from molar ratios (refer to Table 8, above 

for a sample calculation (lb a.i/A)

CCIM-AM 0.147

3

rd Scenario: CTCA 1.137

Aerobic Soil 

Metabolism 

t1⁄2 (days)

Cyazofamid 4.7 Median of 8 values (454091-06/08)

CCIM 1.4 Median of 6 values (454091-07)

CCIM-AM 8.3 Median of 6 values (454091-04)

CTCA 10,000 Considered stable; half-life is >120 days (454091-05)

Koc (L Kg-1)

Cyazofamid 657 Lowest value (454091-12); variations >3 fold

CCIM 690
22

Table 11. Input data for SCI-GROW modeling for EDWCs from ground water for cyazofamid/ degradates

Parameter Value* Reference (MRID Number)

CCIM-AM 2,124 Median of 4 values for each degradate (454091-14)

CTCA 708

* Fate data values are chosen as per Guidance for Selecting Input Parameters in Modeling the Environmental Fate 

and Transport of Pesticides; Version II February 28, 2002.

Table 12. Summary of outputs from SCI-GROW modeling for EDWCs from ground water for cyazofamid.

 Parameter Value/ ppb Source

Screening 

EDWC for 

ground water

1

st Scenario: Parent 0.0118

2 Output from SCI-GROW model runs nd Scenario: CCIM 0.000607

 CCIM-AM 0.00275

3

rd Scenario: CTCA 2.18

It is important to note that modeling for EDWCs from surface and ground water is performed 

using maximum application rate and frequency, and minimum intervals, which allows 

establishing first level values suitable for screening purposes. They may be referred to as likely

upper bound values due to the use of the chemical at the maximum application rate and 

additional refinements can be developed should they be needed. 

Monitoring Data

Monitoring data provide different kinds of information than modeling estimates. For example,

monitoring data consist of actual information from the field, reflecting current use pattern and

usually underestimating frequency of occurrence. Monitoring data does not always include peak 

values, and inputs for monitoring cannot be adjusted as modeled ones can. In addition, 

monitoring is often conducted for purposes other than characterizing exposure from a particular 

pesticide, and as a consequence is used to complement modeling rather than to refine it. In 

general, a useful interpretation of monitoring values requires in-depth assessment of the data, 

which is beyond the scope of a Tier I assessment.

Cyazofamid is a relatively new fungicide and no surface water monitoring data is available.

Drinking Water Treatment

There are no data available related to drinking water treatment of cyazofamid and its degradates.

EXPOSURE CHARACTERIZATION

A drinking waters assessment was performed for cyazofamid and EDWCs were obtained for the 

parent and degradates CCIM, CCIM-AM and CTCA. These degradates were modeled as per 
23

request of HED. They were present at high concentrations, were persistent and/ or were judged 

to have a high degree of toxicity. Preliminarily, HED needs are point estimates (as opposed to 

distributions).

Four standard crop scenarios were utilized to represent fruiting vegetables2and grapes (East of 

the Rocky Mountains). Fruiting vegetables were represented by CA tomato, FL pepper and PA 

tomato. These scenarios are located in a variety of sites in the nation and could be considered 

representative of the proposed use areas. Furthermore, based on the crops represented1, the 

tomato and pepper crops are appropriate crop scenarios. Grapes were represented by the 

standard scenario NY grape. This is the only grape scenario available in the East of the nation. 

Additional scenarios not considered in this assessment include: FL tomato (not used because 

another FL scenario was utilized); CA grape and CA wine grape RLF (these scenarios are not 

located in the intended use sites, also the CA wine grape scenario was developed for red legged 

frog endangered species assessments); and PA vegetable NMC and S TX vegetable NMC (these 

are regional scenarios).

For fruiting vegetables and grapes, the labeled range of application rates is 0.054 to 0.071 lb 

a.i./A per application. In addition, fruiting vegetables for greenhouse transplant production may

receive applications at 0.078 lb a.i./A when used against Pythium spp. The maximum 

application rate of 0.071 lb a.i./A (for outdoor applications) was used in all instances. For 

resistance management, not more than 6 sprays of the product are allowed for both fruiting 

vegetables and grapes. Also, not more than 3 consecutive applications of cyazofamid are 

allowed, and at least 3 applications of other fungicides with different mode of action should be 

alternated. The interval between applications is 7-10 days for fruiting vegetables, and 10-14 

days for grapes. The minimum interval between applications was used in all instances. It is

unknown if the maximum application rate with the minimum interval between applications 

would be typically used. The label instructs to use the lowest rate with the longest intervals for 

preventative applications or for very low disease pressure. There are no usage data readily 

available that would indicate the percent crop area treated (PCA) for the new crops. The national 

default of 87% (used for all “other crops”) was assumed for all runs, all of which adds 

conservativeness to the assessment. A regional restriction for grapes is the use on the East of the 

Rocky Mountains.

EDWCs for cyazofamid and degradates were calculated for drinking water based on half-lives 

obtained from supplemental aerobic soil and aerobic/anaerobic water/sediment metabolism 

studies. In these studies, suspected poor extraction may have underestimated the half-lives of 

cyazofamid and degradates possibly resulting in lower model values for the EDWCs. In this 

respect, it is noted that major identified degradates (CCIM, CCIM-AM and CTCA) may not 

constitute a significant part of the late accumulated un-characterized bound residue (due to the 

apparent adequate extraction of these degradates); however, a degree of uncertainty exists in 

such estimates until new studies with proven extraction procedures are submitted. No data were 

submitted by the registrant to suggest that reasonable attempts were made to extract or analyze 

significant soil or sediment bound radioactivity. Complete characterization of the fate of 

cyazofamid requires data to prove that no parent or degradates were left as part of the bound 

 

2 They include okra, tomato, ground cherry, tomatillo, bell pepper, chili pepper, cooking pepper, pimento, sweet 

peppers, eggplant and pepino plus okra.
24

residue and to characterize various other components that may be present. As a result, EFED is 

requiring additional fate information/data be submitted to assess the impact of these residues on 

the environment.

For SCI-GROW, a complete input dataset was available from submitted studies, but the aerobic 

soil metabolism half-lives were from supplemental studies. For CTCA, an aerobic soil 

metabolism half-life of 10,000 days (>27 years) was assumed, since no degradation occurred in 

the available study (MRID 45409105; three soils, two radiolabels).

In this assessment the total residue method (or approach) was not used. Each metabolite of 

concern was modeled separately. The structures of all three relevant degradates are the result of 

the loss of the sulfonamide moiety. The fate behavior and other characteristics of the degradates 

may not resemble the ones for the parent. There is uncertainty in the input parameters for the 

degradates since no aquatic metabolism (aerobic or anaerobic), solubility, vapor pressure and 

Henry’s Law Constant were available. Certain assumptions were made. For the parent and for 

all the degradates (CCIM, CCIM-AM and CTCA), in PRZM/ EXAMS, the vapor pressure, 

Henry’s Law Constant and solubility were assumed to be the same.

There were 8 half-lives for aerobic soil metabolism of the parent, and 6 for each of the 

degradates. The upperbound value (90th percentile) was used in each case as input for PRZM, as 

indicated by the input parameter guidance. The fact that there were multiple aerobic soil halflives reduces the uncertainty in this input parameter considerably. Nevertheless, with respect to 

the aerobic aquatic metabolism input for EXAMS, there were no studies for the degradates, and 

2x the aerobic soil metabolism input was used, as per guidance. It was noted that for the parent, 

based on laboratory data, the aerobic aquatic metabolism input value (16.4 days) is roughly 3x 

the aerobic soil metabolism input value (5.5 days). In the case of the anaerobic aquatic 

metabolism input, there was only one half-life for the parent, and it was multiplied by a 3x factor 

to get the input used in the model. The 3x factor is used to account for the uncertainty 

surrounding the fact that only one half-life was available. For the degradates there was no data, 

and they were assumed stable to anaerobic aquatic metabolism. The impact of this assumption is 

to overestimate the EDWCs if the chemicals are not in fact persistent in anaerobic media.

The depth of incorporation selected for the parent, cyazofamid, was 0.0 cm (appropriate for 

spray or foliar aerial or ground applications). For the degradates, it was assumed to be 5.08 cm 

(2 inches) to mimic the formation of the degradates on the top soil layer. For the degradates, a 

spray drift value of 6.4% or 16% was utilized (for ground or aerial applications, respectively). 

The drift was modeled this way because the degradates may be formed in surface waters. For 

both the parent and all the degradates, the KOC model was determined to be appropriate (as 

opposed to the Kd model). Individual mobility data were available for all the degradates. The 

aqueous photolysis half-life for the parent cyazofamid is very short (0.02 days or around 30 

min). Aqueous photolysis is expected to occur more often in clear shallow waters, where the 

sunlight is able to penetrate; the process is expected to result in the formation of various 

degradates. Based on its decline in the parent aqueous photolysis study, a half-life of 31.5 days 

was derived for CCIM and utilized in modeling. For the aqueous photolysis, the input parameter 

guidance does not stipulate the use of a factor (e.g. 3x) in any case; there may be uncertainty 

regarding the use of such a short half-life.
25

Environmental fate data reported in the TOXNET (HSDB) database is generally consistent with 

the data available directly to the Agency; no other sources of fate data were identified (e.g. an

EU DAR or a PMRA regulatory note).

Of the three fruiting vegetables crop scenarios tested, CA tomato, FL pepper and PA tomato, the 

FL pepper scenario yielded the highest peak EDWC (refer to Table 10), while the PA tomato 

yielded the highest chronic EDWCs (though lower than for NY grapes). For the uses on turf and 

ornamentals, the surface water acute EDWC is 38.2 ppb. The surface water non-cancer chronic

value is 133.5 ppb and the cancer chronic EDWC is 77.3 ppb (Table 1). By comparison, the 

EDWCs for the uses on fruiting vegetables and grapes were as follows: peak 4.23 ppb; noncancer chronic 3.41 ppb; and cancer chronic 2.67 ppb. These EDWCs correspond to 11.1%, 

2.55% and 3.45% of the corresponding values for the uses on turf and ornamentals, respectively.

In this memorandum, the acute EDWCs were obtained from the sum of values of three runs: for 

the parent, for CCIM, and for CCIM-AM. This means that resultant EDWCs may have been 

overestimated and are expected to be conservative because of nearly double counting the 

application rate (full rate for the parent + estimated rates for CCIM and CCIM-AM). On the 

other hand, chronic values were obtained from EDWCs for the terminal degradate, CTCA, which 

was considered persistent to all fate processes, which is unlikely (CTCA would be dissipated 

only by binding and dilution). In addition, 100% conversion of the parent to the degradate was 

assumed (also unlikely). Therefore, the resultant chronic EDWCs are also expected to be highly 

conservative.

Degradates CCTS, HTID, CDTS and p-Toluamide were found as major degradates only in 

aqueous photolysis studies. Significant amounts of CCIM and CCTS form early in the study 

(peak within a day), and show decline afterwards. Meanwhile HTID, CDTS and p-Toluamide 

form/peak late in the studies (within days), and show only slight or no decline under the 

conditions of the aqueous photolysis study. Because of their late formation, possibly persistent 

degradates HTID, CDTS and p-Toluamide are therefore not expected to be important 

components in natural aquatic systems. Previously, the Metabolism Assessment Review 

Committee (MARC) determined that these degradates will not be more toxic than the parent. In 

addition, based on the use pattern, and the nature of parent, aqueous photolysis may not be a 

major route of degradation in most natural environments. Although the MARC recommended 

to exclude these degradates from drinking water assessment, EFED is requesting 

hydrolysis/aerobic soil metabolism studies on the degradate CCTS to confirm that degradates 

HTID, CDTS and p-Toluamide were only photolytic degradates resulting from long exposure to 

light energy in aqueous systems.

This assessment is considered national in scope for fruiting vegetables, but regional for grapes. 

No regional PCAs were used.

Due to the lack of data, the potential impact of drinking water treatment on cyazofamid and its 

degradates concentrations constitute an uncertainty.
26

CONCLUSIONS

The results of this DWA show that the uses that bring the highest exposure to surface and ground 

drinking waters are turf and ornamentals (reported in a previous review). The new uses on 

fruiting vegetables and grapes resulted in lower EDWCs. The results reported represent a 

timeline in which the parent and the degradates CCIM and CCIM-AM are present initially. 

These chemicals contribute to the surface water peak EDWC. Since the formation of the parent 

and two degradates are assumed and modeled (full application rate for the parent, plus estimated 

application rates for the degradates), the peak EDWC is likely an overestimation.

For chronic exposure, the most conservative scenario is 100% conversion of the parent to the 

terminal degradate CTCA. This scenario of 100% conversion was not observed in the aerobic 

soil metabolism studies and is also likely an overestimation of the chronic EDWCs. It is noted 

that the chronic EDWCs are up to three and a half times larger than the peak EDWC.

The ground water EDWC was <6% of the peak and chronic surface water EDWCs, which 

indicates a lower contribution of the chemicals in ground waters. Once again, since 100% 

conversion was assumed to derive ground water values, the EDWCs are possibly overestimated.

There were limitations in the environmental fate dataset for the degradates, which were assumed 

to behave similar to the parent (e.g. lack of vapor pressure, solubility and Henry’s Law 

Constant); however, all three degradates are the result of the loss of the sulfonamide moiety. It is 

possible that they have substantially different physicochemical properties. An important 

weakness of this assessment is that it relies mostly on supplemental studies, bringing uncertainty 

to the EDWCs. A strength of this assessment is the availability of several aerobic soil 

metabolism half-lives for the parent and degradates (≥6). The aerobic soil metabolism data was 

also used to derive the aerobic aquatic metabolism input values for the degradates (the aerobic 

aquatic metabolism input value is 2x the aerobic soil metabolism input value, as per guidance).

This screening-level assessment is considered conservative. A more definitive assessment may

be made, using the same tier 2 surface waters aquatic model (PRZM/ EXAMS). The application 

rates may be refined and possibly regional PCAs may be used.

REFERENCES 

1. U.S. Environmental Protection Agency (2006). Guidance for Developing a Tier I Drinking 

Water Exposure Assessment. F:\USER\SHARE\Policies,Effects Assessments\d.Water 

Assessments\Surface Water\Drinking Water

2. U.S. Environmental Protection Agency. Guidance on Characterization of Drinking Water 

Exposure for Dietary Risk Assessment. Draft EFED Policy.

3. U.S. Environmental Protection Agency (1999) Estimating the Drinking Water Component of 

a Dietary Exposure Assessment. http://www.epa.gov/oppfead1/trac/science/#drinking
27

4. U.S. Environmental Protection Agency (2000a). Development and Use of Distributions of 

Pesticide Concentrations in Drinking Water for FQPA Exposure Assessments. FIFRA SAP 

Meeting – February 29 – March 3, 2000. 

http://www.epa.gov/oscpmont/sap/meetings/2000/index.htm.

5. June 2000: Monitoring Strategies for Pesticides in Surface-Derived Drinking Water. FIFRA 

SAP Meeting – http://www.epa.gov/scipoly/sap/2000/june/finwateronly.pdf

6. U.S. Environmental Protection Agency (2000b). Progress Report on Estimating Pesticide 

Concentrations in Drinking Water and Assessing Water Treatment Effects on Pesticide Removal 

and Transformation. http://www.epa.gov/oscpmont/sap/meetings/2000/index.htm

7. U.S. Environmental Protection Agency (2000c) Drinking Water Screening Level Assessment. 

Part A: Guidance for Use of the Index Reservoir in Drinking Water Exposure Assessments. Part 

B: Applying a Percent Crop Area Adjustment to Tier 2 Surface Water Model Estimates for 

Pesticide Drinking Water Exposure Assessments. FIFRA SAP Meeting – September 1, 2000. 

http://www.epa.gov/oppfead1/trac/science/reservoi.pdf.

8. SCIGROW: Users Manual (11/01/2001, revised 08/23/2002)

9. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of 

Pesticides, Version II (02/28/2002)

10. Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL 

SERIES 8. Assessing Soil Contamination: A Reference Manual. Appendix 2. Parameters of 

pesticides that influence processes in the soil. Editorial Group, FAO Information Division: 

Rome, 2000. http://www.fao.org/DOCREP/003/X2570E/X2570E00.htm
28

Appendix A. Structures of Cyazofamid and Relevant Degradation Products

Cyazofamid [IKF-916]

IUPAC Name: 4-Chloro-2-cyano-N,N-dimethyl-5-p-tolylimidazole-1-sulfonamide.

CAS Name: 4-Chloro-2-cyano-N,N-dimethyl-5-(4-methylphenyl)-1H-imidizole1-sulfonamide.

CAS Number: 120116-88-3.

SMILES String: Cc1ccc(cc1)c1c(nc(n1S(=O)(=O)N(C)C)C#N)Cl

(ISIS v2.3/Universal SMILES).

No EPI Suite, v3.12 SMILES String found as of 6/28/06.

CH3

N N

Cl

C

N

S

O

O

N

CH3

CH3
29

CCIM

IUPAC Name: 4-Chloro-5-p-tolylimidazole-2-carbonitrile.

CAS Name: Not reported.

CAS Number: Not reported.

CCIM-AM

IUPAC Name: 4-Chloro-5-p-tolylimidazole-2-carboxamide.

CAS Name: Not reported.

CAS Number: Not reported.

N NH

Cl

CH3

C

N

N NH

Cl

CH3

CONH2
30

CTCA

IUPAC Name: 4-Chloro-5-p-tolylimidazole-2-carboxylic acid.

CAS Name: Not reported.

CAS Number: Not reported.

N NH

Cl

CH3

COOH
31

Appendix B. Sample Model Outputs

PRZM/EXAMS

For the parent cyazofamid, on CA tomato:

stored as Cyazofam.out

Chemical: Cyazofamid

PRZM environment: CAtomato_WirrigSTD.txt modified Tueday, 29 May 2007 at 11:43:54

EXAMS environment: ir298.exv modified Thuday, 29 August 2002 at 14:34:12

Metfile: w93193.dvf modified Wedday, 3 July 2002 at 08:04:24

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 0.2597 0.1595 0.1089 0.07954 0.05394 0.01333

1962 0.2548 0.1638 0.1136 0.07858 0.0532 0.01314

1963 0.3623 0.2325 0.1517 0.1217 0.08242 0.02036

1964 0.2398 0.1533 0.1072 0.07752 0.05258 0.01296

1965 0.7912 0.5077 0.2352 0.1307 0.08796 0.02172

1966 0.2378 0.1505 0.105 0.07467 0.05045 0.01246

1967 0.4721 0.3414 0.2071 0.1394 0.09402 0.02322

1968 0.2626 0.1686 0.1264 0.08822 0.05961 0.01469

1969 0.255 0.1588 0.106 0.0921 0.06205 0.01533

1970 0.2365 0.1489 0.1037 0.07591 0.05123 0.01265

1971 0.3936 0.2458 0.1536 0.09577 0.06639 0.01642

1972 0.2356 0.1456 0.1012 0.07376 0.05104 0.01298

1973 0.3581 0.2442 0.1602 0.0971 0.06542 0.01616

1974 0.2468 0.1844 0.1273 0.0886 0.0597 0.01474

1975 0.2485 0.1645 0.1185 0.08416 0.05681 0.01403

1976 0.2377 0.1499 0.1045 0.0771 0.05206 0.01324

1977 0.2456 0.1556 0.1109 0.07789 0.05401 0.01334

1978 0.3643 0.2393 0.1507 0.1176 0.07923 0.02079

1979 0.2454 0.1712 0.1189 0.08208 0.05536 0.01367

1980 0.2402 0.154 0.1077 0.07898 0.0535 0.01318

1981 0.3639 0.2517 0.1487 0.09662 0.06517 0.01608

1982 0.3559 0.2392 0.1708 0.1103 0.07425 0.01848

1983 1.274 0.791 0.2659 0.1597 0.11 0.02718

1984 0.2361 0.146 0.1015 0.07474 0.05045 0.01244

1985 0.2406 0.1544 0.1089 0.07653 0.05171 0.01303

1986 0.3111 0.2016 0.143 0.09064 0.06113 0.01509

1987 0.2632 0.1699 0.1207 0.08128 0.06504 0.01607

1988 0.3918 0.2684 0.1728 0.09964 0.06736 0.01659

1989 0.6768 0.4383 0.1809 0.1096 0.07697 0.01907

1990 0.3661 0.2416 0.1348 0.0887 0.07097 0.01763

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258064516129 1.274 0.791 0.2659 0.1597 0.11 0.02718

0.0645161290322581 0.7912 0.5077 0.2352 0.1394 0.09402 0.02322

0.0967741935483871 0.6768 0.4383 0.2071 0.1307 0.08796 0.02172

0.129032258064516 0.4721 0.3414 0.1809 0.1217 0.08242 0.02079

0.161290322580645 0.3936 0.2684 0.1728 0.1176 0.07923 0.02036

0.193548387096774 0.3918 0.2517 0.1708 0.1103 0.07697 0.01907

0.225806451612903 0.3661 0.2458 0.1602 0.1096 0.07425 0.01848

0.258064516129032 0.3643 0.2442 0.1536 0.09964 0.07097 0.01763

0.290322580645161 0.3639 0.2416 0.1517 0.0971 0.06736 0.01659

0.32258064516129 0.3623 0.2393 0.1507 0.09662 0.06639 0.01642

0.354838709677419 0.3581 0.2392 0.1487 0.09577 0.06542 0.01616

0.387096774193548 0.3559 0.2325 0.143 0.0921 0.06517 0.01608

0.419354838709677 0.3111 0.2016 0.1348 0.09064 0.06504 0.01607

0.451612903225806 0.2632 0.1844 0.1273 0.0887 0.06205 0.01533

0.483870967741936 0.2626 0.1712 0.1264 0.0886 0.06113 0.01509

0.516129032258065 0.2597 0.1699 0.1207 0.08822 0.0597 0.01474

0.548387096774194 0.255 0.1686 0.1189 0.08416 0.05961 0.01469

0.580645161290323 0.2548 0.1645 0.1185 0.08208 0.05681 0.01403

0.612903225806452 0.2485 0.1638 0.1136 0.08128 0.05536 0.01367

0.645161290322581 0.2468 0.1595 0.1109 0.07954 0.05401 0.01334

0.67741935483871 0.2456 0.1588 0.1089 0.07898 0.05394 0.01333
32

0.709677419354839 0.2454 0.1556 0.1089 0.07858 0.0535 0.01324

0.741935483870968 0.2406 0.1544 0.1077 0.07789 0.0532 0.01318

0.774193548387097 0.2402 0.154 0.1072 0.07752 0.05258 0.01314

0.806451612903226 0.2398 0.1533 0.106 0.0771 0.05206 0.01303

0.838709677419355 0.2378 0.1505 0.105 0.07653 0.05171 0.01298

0.870967741935484 0.2377 0.1499 0.1045 0.07591 0.05123 0.01296

0.903225806451613 0.2365 0.1489 0.1037 0.07474 0.05104 0.01265

0.935483870967742 0.2361 0.146 0.1015 0.07467 0.05045 0.01246

0.967741935483871 0.2356 0.1456 0.1012 0.07376 0.05045 0.01244

0.1 0.65633 0.42861 0.20448 0.1298 0.087406 0.021627

Average of yearly averages: 0.0160023333333333

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:

Output File: Cyazofam

Metfile: w93193.dvf

PRZM scenario: CAtomato_WirrigSTD.txt

EXAMS environment file: ir298.exv

Chemical Name: Cyazofamid

Description Variable Name Value Units Comments

Molecular weight mwt 324.79 g/mol

Henry's Law Const. henry 4e-7 atm-m^3/mol

Vapor Pressure vapr 1e-7 torr

Solubility sol 1.07 mg/L

Kd Kd mg/L

Koc Koc 1338 mg/L

Photolysis half-life kdp 0.02 days Half-life

Aerobic Aquatic Metabolism kbacw 16.4 days Halfife

Anaerobic Aquatic Metabolism kbacs 17.7 days Halfife

Aerobic Soil Metabolism asm 5.5 days Halfife

Hydrolysis: pH 7 11.9 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0.0 cm

Application Rate: TAPP 0.0850 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.064 fraction of application rate applied to pond

Application Date Date 11-03 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 7 days Set to 0 or delete line for single app.

app. rate 1 apprate 0.0850 kg/ha

Interval 2 interval 7 days Set to 0 or delete line for single app.

app. rate 2 apprate 0.0850 kg/ha

Interval 3 interval 21 days Set to 0 or delete line for single app.

app. rate 3 apprate 0.0850 kg/ha

Interval 4 interval 7 days Set to 0 or delete line for single app.

app. rate 4 apprate 0.0850 kg/ha

Interval 5 interval 7 days Set to 0 or delete line for single app.

app. rate 5 apprate 0.0850 kg/ha

Record 17: FILTRA

IPSCND 1

UPTKF 0

Record 18: PLVKRT 0

PLDKRT 0

FEXTRC 0.5

Flag for Index Res. Run IR Reservoir

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)
33

SCI-GROW

Sample run for CTCA:

 SCIGROW

 VERSION 2.3

 ENVIRONMENTAL FATE AND EFFECTS DIVISION

 OFFICE OF PESTICIDE PROGRAMS

 U.S. ENVIRONMENTAL PROTECTION AGENCY

 SCREENING MODEL

 FOR AQUATIC PESTICIDE EXPOSURE

SciGrow version 2.3

chemical:CTCA_Scenario_3

time is 2/12/2009 8:37:57

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

 rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------

 1.137 2.0 2.274 7.08E+02 10000.0

------------------------------------------------------------------------

groundwater screening cond (ppb) = 2.18E+00 

************************************************************************
34

Attachment B. ELECTRONIC COPY OF DWA DATED 09/06/06

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFFICE OF PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

PC Code No.: 085651

DP Barcode: D319466

Date: September 6, 2006

MEMORANDUM

SUBJECT: Estimated Drinking Water Concentrations of Parent Cyazofamid and its 

Degradates CCIM, CCIM-AM and CTCA for Use in Human Health Risk 

Assessment (Turf and ornamentals use pattern).

FROM: Mohammed A. Ruhman, Agronomist, Ph.D.

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

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

Environmental Risk Branch V

Environmental Fate and Effects Division (7507P)

TO: Cynthia Giles-Parker, Chief

Tony Kish, PM Team Reviewer

Janet Whitehurst, Risk Manager Reviewer

Fungicide Branch

Registration Division (7505P)

AND: Kelly Orourke

Health Effects Division

Summary

This memo presents the Estimated Drinking Water Concentrations (EDWCs) for Parent 

Cyazofamid and degradates CCIM, CCIM-AM and CTCA for use in an FQPA human health risk 

assessment. Cyazofamid fungicide and/or degradates may reach both surface and groundwater 

under some conditions. The registrant is seeking registration for use of this new chemical on turf 

and ornamentals. It is noted that EDWCs were previously estimated for cucurbits, potatoes, and 

tomatoes (EFED Memo to HED dated April 28, 2004).

The screening level surface water and ground water estimates are calculated using tier 2 

linked PRZM/EXAMS models and the tier 1 SCI-GROW model, respectively. Resultant 
35

Estimates are presented in Table 1 for three scenarios as follows:

(1) 1st scenario (parent) assuming application of the maximum rate as parent;

(2) 2

nd scenario (each of the degradates CCIM, CCIM-AM, and CTCA) assuming application of 

the molar equivalent of the parent for each of the degradate by dividing the rate between the 

degradates based on molecular ratios and adjusted maximums found in fate studies; and

(3) 3rd scenario (the terminal degradate CTCA) assuming application of 100% molar conversions 

of the parent into this terminal degradate CTCA.

Table 1. Resultant maximums of surface/ground water EDWCs for cyazofamid and each of its 

major degradates.

Scenario

Chemical

Surface water EDWCs (ppb)

Ground water 

Acute EDWC (ppb)

Chronic “noneCancer”Chronic 

“Cancer”

1

st

 Scenario Parent 14.362 0.377 0.279 0.01180

2

nd

 Scenario 

CCIM 17.106 12.094 10.600 0.00061

CCIM-AM 6.699 6.312 3.611 0.00270

CTCA 16.716 11.993 8.886 0.52300

3

rd

 Scenario CTCA 136.242 133.458 77.270 2.18000

Based on the results presented in Table 1 above and time-line of exposure, the surface water

acute EDWC is 38.167 ppb (total value= Parent “14.362 ppb” + CCIM “17.106 ppb” + CCIMAM “6.699 ppb”). CTCA is not included in the surface water acute number because it is not 

expected to be present at this time frame. The surface water none-cancer chronic is 133.458 

ppb and the cancer chronic is 77.270 pp (equal to the value for the terminal degradate CTCA). 

For ground water, the acute/chronic value is 2.18 ppb (equal to the value for the terminal 

degradate CTCA). 

The above stated values represent upper-bound estimates of the parent, individual degradates

and/or terminal degradate CTCA concentrations that might be found in surface water and 

groundwater due to the use of cyazofamid on turf and ornamentals. EFED emphasizes that this is 

a tier 1 screening level analysis, and should there be a need by HED, additional refinements can 

be made.

Environmental Fate of Cyazofamid

Available environmental fate studies suggest cyazofamid is not very mobile and quickly

degrades into a number of degradation products under different environmental conditions. 

Among the three major degradates for Cyazofamid (CCIM, CCIM-AM and CTCA), the two 

terminal ones are CCIM and CTCA. CCIM is expected to be the major terminal degradate in 

water bodies with low biological activity because it forms as a result of abiotic hydrolysis of the 

parent. In contrast, CTCA is expected to be the major terminal degradate in biologically active 

soils and water/sediment systems. Both CCIM and CTCA are stable to abiotic hydrolysis and 

susceptible to leaching but only CCIM is highly susceptible to biodegradation. Given these fate 
36

characteristics, cyazofamid could potentially reach surface water via spray drift or runoff under 

certain environmental conditions but the potential for it to reach ground water is very low. CCIM 

and/or CTCA could potentially be the terminal degradates in surface water bodies affected by

spray drift and/or runoff depending on the level of biological activity. However, only CTCA has 

a high potential to contaminate groundwater due to its high persistence and mobility. This 

assessment addresses exposure to parent cyazofamid and its degradation products CCIM, CCIMAM and CTCA.

Procedure for calculating EDWCs for cyazofamid and its degradates

Cyazofamid is a new fungicide and no surface water monitoring data is available. For this 

reason, the Agency based this report on simulated screening values using modeling. The 

screening level surface water and ground water estimates are calculated using tier 2 linked 

PRZM/EXAMS models and the tier 1 SCI-GROW model, respectively. It should be noted 

that: 

(1) Water numbers for cyazofamid and its degradates were generated from the models in which 

the Koc and aerobic soil half-life values used were obtained from supplemental studies; 

(2) Solubility of the degradates were considered to be the same as parent (0.107 ppm); 

(3) Direct photolysis half-life for the degradate CCIM was estimated from its formation and 

decline curve in the aqueous direct photolysis study of the parent (half-life= 31.52 days); 

(4) The degradates CCIM-AM and CTCA were considered to be stable to direct photolysis in 

water as it was not identified in parent aqueous direct photolysis and therefore, half-lives could 

not be calculated; and 

(5) The initial residue levels for degradates used in the models were based on molecular ratios; 

assuming time zero 100% conversion of parent to a mixture of degradates based on weight 

adjusted maximums in fate studies. EFED acknowledges that this assumption is reasonable but 

conservative. The calculated initial residue levels are presented in Table 2.

Table 2. An example (Turf) for calculating the initial residue levels used in modeling (i.e. 

application rates).

Chemical

Molecular 

Weight *

Molecular 

Ratio

Determined Maximum (% Parent Equivalent)

Example Application Rate** 

Value Adjusted Value Fate Study Used (lb a.i./Acre for turf)

Parent 324.79 1 100% 100% Assumed 1.01990

CCIM 217.66 0.6702 83% 63% Hydrolysis 0.43063

CCIM-AM 235.67 0.7256 17% 13% Anaerobic Aquatic 0.09621

CTCA 236.66 0.7287 31% 24% Aerobic Aquatic 0.17837

Total 131% 100%

CTCA 236.66 0.7287 100% 100% Assumed 0.74320

* Molecular Weights for degradates of cyazofamid were calculated by deduction of elements lost from parent 

structure.

** Rate for each degradates= Parent Rate x Molecular Ratio x adjusted maximum found in fate studies; for example 

the rate for CCIM= 1.01990 x 0.6702 x 63% = 0.43063 lb a.i/A.

Based on the procedure explained by Table 1, Application rates for the different runs are 

calculated and included in Table 3. Modeled scenarios and additional information are included 
37

in Table 4.

Table 3. Crop use pattern information used in modeling of cyazofamid and degradates (separate 

modeling for three different scenarios).

Scenario

Modeled 

Chemical

Label or Calculated Maximum Application Rates (Kg/Ha and “ lb/A”)

Turf Foliar Applied Ornamentals

Soil Applied/Drip Irrigation Applied

Bedded Ornamentals

First Parent 1.1433

“1.0199”

0.1750

“0.1561”

1.7498

“1.5609”

Second

CCIM 0.4827 0.0739 0.7388

CCIM-AM 0.1078 0.0165 0.1651

CTCA 0.2000 0.0306 0.3060

Third CTCA 0.8331 0.1275 1.2751

* By multiplying label rates in lb/A by 1.121 for example: 1.0199x1.121= 1.1433 kg/ha.

Table 4. PRZM/EXAMS modeled crop scenarios* with application dates/number of applications 

(note: application interval= 14 days for all listed crops).

Scenario Application Date(s)”dd/mm Number of Applications

Florida Turf 15-03; 15-04; and 15-05 3

Pennsylvania Turf 01-07; 15-07; and 30-07 3

Oregon Christmas Trees 15-06; 30-06; and 15-07 2

* Two runs were executed for each scenario/chemical/application procedure and date combinations: the first with 

0% drift and the second with 6.4 or 16% drift (total number of runs= 5 chemicals (parent, CCIM, CCIM-AM, 

CTCA, and CTCA alone) x 24 (2 runs x 4 scenarios/application procedures x 3 dates) = 120. 

Background information on PRZM/EXAMS models are included in Appendix I; fate and 

transport input parameters are summarized in Table 5.

Table 5. Cyazofamid: PRZM/EXAMS input parameters for modeling surface water EDWCs.

Input Parameter Chemical Value Reference

Molecular Weight 

(gram mole -1)

Parent 324.79

MRID 454090-38

CCIM 217.66

CCIM-AM 235.67

CTCA 236.66

Vapor Pressure 

(torr) All 1.316x10-10 MRID 454090-38

Aerobic Soil

Metabolism Halflife (days)

Parent 5.5

The 90th percentile t1⁄2 from eight values for the parent and 

six values fore ach degradate (MRIDs 454091 

06/08/07/04/05).

CCIM 2.2

CCIM-AM 13.6

CTCA Stable
38

Input Parameter Chemical Value Reference

Water column 

Half-life (days)

(Aerobic Aquatic 

Metabolism halflife)

Parent 16.4

The 90th percentile t1⁄2 from four values for the parent 

(MRID 454091-10). For the degradates: Considered stable 

as no significant hydrolysis at pH 7 as per Guidance (US 

EPA, 2002)

CCIM

Stable

CCIM-AM

CTCA

Benthic sediment 

Half-life (days) 

(Anaerobic 

Aquatic 

Metabolism halflife)

Parent 17.7 One half-life value; 3x5.9=17.7 (MRID 454091-09)

Both Stable No anaerobic metabolism data

Application Rate 

(Kg a.i./ha) Refer to Table 3 (Efficiency= 0.95 for aerial spray and 0.99 for ground spray).

Application 

Number (Method 

of application) All; Refer to Table 4 Product Label; with 14-day application intervals

Depth of 

Incorporation (cm)

Parent 0

CAM=2 for parent/foliage application (Product Label); 

CAM=1 for the degradates (degradates are expected to form 

in the top soil from parent; CAM=1=linear distribution in 

Degradates 7.5 the top 4 cm)

Spray Drift 

(fraction)

All: 0 or 0.16 (Aerial)

Or 0.064 (Ground)

0% for application via drip irrigation; 16% default drift for 

Aerial; and 6.4% default drift for Ground 

Solubility (ppm) All 0.107 MRID 454090-38

Koc (L Kg-1)

Parent 1,338 Parent: Average of eight values (MRID 454091-12). 

Degradates: Average of four values for each of degradates 

(MRID 454091-14). 

Koc model was determined to be appropriate.

CCIM 753

CCIM-AM 2,397

CTCA 836

Hydrolysis Halflife @ pH 7 (days)

Parent 11.9 Maximum value at pH 7 (MRID 454090-39) 

CCIM

Stable MRID 454091-01

CCIM-AM

CTCA

Direct Aqueous 

Photolysis Halflife(days)

Parent 0.02

CCIM 31.5 Maximum dark control corrected value (MRID 454091-02)

Degradates Stable No data
39

Results of PRZM/EXAMS modeling is summarized in Table 6 with an example runs included 

in the Appendix II. It is noted that no Percent Crop Area (PCA) was applied to turf while a 

PCA of 0.87 was applied to x-mass trees.

Table 6. Summary of PRZM/EXAMS results (EDWCs in ppb)

Scenario (Crop & Application) Chemical Peak 96 hr 21 Day 60 Day 90 Day Yearly All Years Drift*

FL turf (03/15, 04/15) and

PA turf (07/01&30)

(Aerial to Turf Foliage) Parent 14.362 9.169 4.053 2.278 1.528 0.377 0.279 18%

PA turf 07/01,15&30)

(Aerial to Turf Foliage)

CCIM 17.106 16.937 16.358 15.373 14.857 12.094 10.600 91%

CCIM-AM 4.142 4.064 3.800 3.557 3.407 2.921 2.401 81%

CTCA 16.716 16.538 15.839 14.594 13.866 11.993 8.886 37%

PA turf (07/01&30)

(Aerial to Turf Foliage) CTCA 69.661 68.893 65.979 60.792 57.758 49.958 37.024 37%

OR x-mass (03/15&21)

(Ground to Soil planted with 

Ornamentals) Parent 4.470 3.340 1.870 0.833 0.559 0.138 0.114 70%

OR x-mass (03/15)

(Ground to Soil planted with 

Ornamentals)

CCIM 8.191 8.135 7.923 7.538 7.316 6.119 5.552 76%

CCIM-AM 6.699 6.675 6.591 6.486 6.447 6.312 3.611 95%

CTCA 5.693 5.640 5.439 5.106 4.921 4.179 3.659 49%

OR x-mass (03/15)

(Ground to Soil planted with 

Ornamentals) CTCA 136.242 136.155 136.155 135.285 135.198 133.458 77.270 59%

OR x-mass (03/21)

(Through Irrigation to Soil 

planted with Ornamentals) Parent 2.320 1.627 0.570 0.206 0.138 0.034 0.011

OR x-mass 03/15) 0%

(Through Irrigation to Soil 

planted with Ornamentals)

CCIM 1.962 1.932 1.880 1.834 1.802 1.605 0.542

CCIM-AM 0.315 0.314 0.309 0.269 0.263 0.251 0.137

CTCA 2.884 2.847 2.707 2.476 2.357 2.199 1.499

OR x-mass (03/15)

(Through Irrigation to Soil 

planted with Ornamentals ) CTCA 56.138 56.097 55.977 55.336 55.217 54.909 33.703

OR x-mass (06/15)

(Aerial to Ornamental 

Foliage) Parent 0.940 0.644 0.363 0.143 0.097 0.024 0.022 96%

OR x-mass 06/15&30 

and 07/07)

(Aerial to Ornamental 

Foliage)

CCIM 1.864 1.850 1.797 1.703 1.648 1.404 1.244 99%

CCIM-AM 0.437 0.430 0.407 0.381 0.368 0.327 0.258 99%

CTCA 1.121 1.115 1.090 1.047 1.022 0.943 0.771 59%

OR x-mass (06/15&30)

(Aerial to Ornamental 

Foliage) CTCA 4.671 4.644 4.538 4.364 4.258 3.929 3.215 60%

Maximums: Parent+CCIM+CCIM-AM 38.167 CTCA only 133.458 77.270

* % of exposure resulting from drift (based on initial drift/peak values from 1 in 10 years data).

For ground water, SCI-GROW program, a high exposure tier one model, was used to arrive at 

the Estimated Drinking Water Concentration (EDWC) for this chemical and its degradates from 

ground water sources. Background information on SCI-GROW model is included in the 

Appendix II and input/output values are summarized in Tables 7 and 8.
40

Table 7. Summary of inputs for SCI-GROW modeling for EDWCs from ground water for 

cyazofamid/degradates.

Parameter Value* 

Reference (MRID Number)

Crop/ Seasonal No. of Applications

Soil Applied to 

Ornamentals/2 High Exposure (maximum rate/number); Product label

Label 

Application 

Rate (lb 

a.i./acre)

1

st Scenario: Parent 1.5609 Product label (lb a.i/A)

2

nd Scenario: CCIM 0.6591

Calculated from molar ratios (lb a.i/A)

CCIM-AM 0.1472

CTCA 0.2730

3

rd Scenario: CTCA 1.1374

Aerobic Soil 

Metabolism 

t1⁄2 (days)

Cyazofamid 4.7 Median of 8 values (454091-06/08)

CCIM 1.4 Median of 6 values (454091-07)

CCIM-AM 8.3 Median of 6 values (454091-04)

CTCA 10,000 Considered stable; half-life is >120 days (454091-05)

Koc (L Kg-1)

Cyazofamid 657 Lowest value (454091-12); variations >3 fold

CCIM 690

Median of 4 values for each degradate (454091-14)

CCIM-AM 2,124

CTCA 708

* Fate data values are as per Guidance for Selecting Input Parameters in Modeling the Environmental Fate and 

Transport of Pesticides; Version II February 28, 2002.

Table 8. Summary of outputs from SCI-GROW modeling for EDWCs from ground water for 

cyazofamid/degradates.

Parameter Value* Reference (MRID Number)

EDWC for 

ground water 

screening

1

st Scenario: Parent 0.01180 Output for one Model Run

2

nd Scenario: CCIM 0.00061

Outputs for three Model Runs

CCIM-AM 0.00270

CTCA 0.52300

3

rd Scenario: CTCA 2.18000 Output for one Model Run

It is important to note that modeling for EDWCs from surface and ground water is performed 

using the single application rate of 1.5609 lb a.i/A applied 2 times to soil planted with 

ornamentals. This represents the highest seasonal application rate among the identified four types 

of applications. However, using this application rate/frequency allows establishing first level 

values suitable for screening purposes. They may be referred to as likely upper bound values due 

to the use of the chemical at the maximum application rate and additional refinements can be 

developed should they be needed. 
41

Uncertainties

EDWCs for cyazofamid and degradates were estimated for drinking water based on half-lives 

calculated from supplemental aerobic soil and aerobic/anaerobic water/sediment laboratory fate 

studies. In these studies, suspected lack of extraction may have underestimated the half-lives of 

cyazofamid and degradates possibly resulting in lower model estimates for the EDWCs. In this 

respect, it is noted that major identified degradates (CCIM, CCIM-AM and CTCA) may not

constitute a significant part of the late accumulated un-characterized bound residue (due to the 

apparent adequate extraction of these degradates); however, a degree of uncertainty exists in 

such estimates until new studies with proven extraction procedures are submitted. No data were 

submitted by the registrant suggested that attempts were made to extract or analyze significant 

soil or sediment bound radioactivity. Complete characterization of the fate of cyazofamid 

requires data to prove that no parent or degradate was left as part of the bound residue and to 

characterize various other components that may be present. As a result, EFED is requiring 

additional fate information/data be submitted to assess the impact of these residues on the 

environment.

In this Memo, the acute values were obtained from summation of EECs of three runs: Parent 

alone, CCIM degradate, and CCIM-AM degradate. This means that resultant EDWCs are 

expected to be conservative because of nearly double counting of the application rate (full rate 

for parent + equivalent rates for CCIM and CCIM-AM). On the other hand, chronic values were 

obtained from EECs for the terminal degradate which was considered to be stable in all of its fate 

parameters. Therefore, the resultant EDWCs are expected to be highly conservative. 

Degradates CCTS, HTID, CDTS and p-Toluamide were found as major degradates only in 

aqueous direct photolysis. Significant amounts of CCIM and CCTS form early (within a day), 

peak and show clear decline while HTID, CDTS and p-Toluamide form/peak late (within days) 

and show only slight or no decline under the conditions of the direct photolysis experiment. 

Persistent degradates HTID, CDTS and p-Toluamide are therefore not expected to be important 

components in natural aquatic systems because of their late formation. MARC also believes that 

none of these degradates will be more toxic than the parent. In addition, based on the use 

pattern, and the nature of parent, aqueous direct photolysis may not be a major route of 

degradation in most natural environments. The Metabolism Assessment Review Committee 

(MARC) recommended to exclude these degradates from drinking water assessment. However, 

EFED will ask the registrant for hydrolysis/aerobic soil studies on the degradate CCTS to 

confirm that degradates HTID, CDTS and p-Toluamide were only photolytic degradates 

resulting from long exposure to light energy. 
42

APPENDIX I: Background information on PRZM/EXAMS 

a. PRZM and EXAMS models and the Index Reservoir Scenario

The linked PRZM and EXAMS models are used in this case as a second tier screen designed to 

estimate the pesticide concentrations found in water for use in drinking water assessments. They

provide high-end values on the concentrations that might be found in a small drinking water 

reservoir due to the use of pesticide. The Drinking Water Index Reservoir scenario includes a 

427 acres field immediately adjacent to a 13 acres reservoir, 9 feet deep, with continuous sitespecific flow. This amount can be reduced due to degradation in field and the effect of binding to 

soil. Spray drift is equal to 6.4% of the applied concentration from the ground spray application 

and 16% for aerial applications.

The PRZM/EXAMS modeling system with the Index Reservoir scenario also makes adjustments 

for the percent cropped area. While it is assumed that the entire watershed would not be treated, 

the use of a PCA is still a screen because it represents the highest percentage of crop cover of 

any large watershed in the US, and it assumes that the entire crop is being treated. Various other 

conservative assumptions of this scenario include the use of a small drinking water reservoir 

surrounded by a runoff-prone watershed, the use of the maximum use rate and no buffer zone.

b. SCI-GROW

SCI-GROW is a screening model which the Office of Pesticide Programs (OPP) in EPA 

frequently uses to estimate pesticide concentrations in vulnerable ground water. The model 

provides an exposure value which is used to determine the potential risk to the environment and 

to human health from drinking water contaminated with the pesticide. The SCI-GROW estimate 

is based on environmental fate properties of the pesticide (aerobic soil degradation half-life and 

linear adsorption coefficient normalized for soil organic carbon content), the maximum 

application rate, and existing data from small-scale prospective ground-water monitoring studies 

at sites with sandy soils and shallow ground water.

Pesticide concentrations estimated by SCI-GROW represent conservative or high-end exposure 

values because the model is based on ground-water monitoring studies which were conducted by

applying pesticides at maximum allowed rates and frequency to vulnerable sites (i.e., shallow 

aquifers, sandy, permeable soils, and substantial rainfall and/or irrigation to maximize leaching). 

In most cases, a large majority of the use areas will have ground water that is less vulnerable to 

contamination than the areas used to derive the SCI-GROW estimate. SCI-GROW provides a 

groundwater screening exposure value to be used in determining the potential risk to human 

health from drinking water contaminated with the pesticide. SCI-GROW estimates likely

groundwater concentrations if the pesticide is used at the maximum allowable rate in areas where 

groundwater is exceptionally vulnerable to contamination. In most cases, a large majority of the 

use area will have groundwater that is less vulnerable to contamination than the areas used to 

derive the SCI-GROW estimate.
43

APPENDIX II: MODEL RUNS & BACKGROUND INFORMATION

PRZM/EXAMS

Florida Turf (March 15) Parent with drift

stored as DW.out

Chemical: Cyazofamid

PRZM environment: 

FLturfC.txt modified Monday, 16 June 2003 at 13:48:06

EXAMS environment: 

ir298.exv modified Thuday, 29 August 2002 at 15:34:12

Metfile: w12834.dvf modified Wedday, 3 July 2002 at 09:04:28

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 6.834 4.27 2.226 1.257 0.8414 0.208

1962 6.869 4.372 2.325 1.309 0.8744 0.2294

1963 6.841 4.285 2.251 1.273 0.8784 0.2172

1964 11.27 7.006 2.798 2.115 1.424 0.3504

1965 6.886 4.422 2.364 1.319 0.897 0.2386

1966 7.61 4.699 3.33 1.797 1.232 0.3046

1967 6.822 4.22 2.201 1.238 0.9504 0.2376

1968 6.828 4.244 2.239 1.267 0.9261 0.2306

1969 6.9 4.462 2.396 1.337 0.9752 0.2408

1970 7.065 4.45 2.579 1.43 0.961 0.2372

1971 7.227 4.459 2.692 1.429 0.9971 0.2465

1972 15.9 9.837 4.431 2.042 1.378 0.3394

1973 6.93 4.325 2.384 1.333 0.8906 0.2197

1974 7.157 4.44 2.452 1.326 0.8921 0.2205

1975 7.849 4.843 2.45 1.351 0.9029 0.2229

1976 14.86 9.012 4.535 2.13 1.464 0.3605

1977 6.821 4.215 2.194 1.214 0.8506 0.21

1978 14.67 8.711 3.309 2.004 1.343 0.3316

1979 6.811 4.157 2.18 1.343 0.9099 0.2245

1980 6.883 4.336 2.401 1.362 0.9159 0.2255

1981 6.875 4.308 2.282 1.263 0.8597 0.2124

1982 9.224 5.767 3.532 1.799 1.221 0.3029

1983 9.63 6.466 3.005 1.596 1.07 0.264

1984 9.067 5.597 3.495 1.703 1.166 0.2871

1985 6.814 4.861 2.368 1.31 0.8752 0.216

1986 6.815 4.189 2.169 1.188 0.7933 0.1972

1987 11.59 7.921 3.395 1.729 1.156 0.2853

1988 6.821 4.219 2.201 1.249 0.8366 0.2059

1989 6.823 4.225 2.205 1.303 0.8713 0.215

1990 6.802 4.134 2.133 1.199 0.8007 0.1975

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258065 15.9 9.837 4.535 2.13 1.464 0.3605

0.064516129 14.86 9.012 4.431 2.115 1.424 0.3504

0.096774194 14.67 8.711 3.532 2.042 1.378 0.3394
44

0.129032258 11.59 7.921 3.495 2.004 1.343 0.3316

0.161290323 11.27 7.006 3.395 1.799 1.232 0.3046

0.193548387 9.63 6.466 3.33 1.797 1.221 0.3029

0.225806452 9.224 5.767 3.309 1.729 1.166 0.2871

0.258064516 9.067 5.597 3.005 1.703 1.156 0.2853

0.290322581 7.849 4.861 2.798 1.596 1.07 0.264

0.322580645 7.61 4.843 2.692 1.43 0.9971 0.2465

0.35483871 7.227 4.699 2.579 1.429 0.9752 0.2408

0.387096774 7.157 4.462 2.452 1.362 0.961 0.2386

0.419354839 7.065 4.459 2.45 1.351 0.9504 0.2376

0.451612903 6.93 4.45 2.401 1.343 0.9261 0.2372

0.483870968 6.9 4.44 2.396 1.337 0.9159 0.2306

0.516129032 6.886 4.422 2.384 1.333 0.9099 0.2294

0.548387097 6.883 4.372 2.368 1.326 0.9029 0.2255

0.580645161 6.875 4.336 2.364 1.319 0.897 0.2245

0.612903226 6.869 4.325 2.325 1.31 0.8921 0.2229

0.64516129 6.841 4.308 2.282 1.309 0.8906 0.2205

0.677419355 6.834 4.285 2.251 1.303 0.8784 0.2197

0.709677419 6.828 4.27 2.239 1.273 0.8752 0.2172

0.741935484 6.823 4.244 2.226 1.267 0.8744 0.216

0.774193548 6.822 4.225 2.205 1.263 0.8713 0.215

0.806451613 6.821 4.22 2.201 1.257 0.8597 0.2124

0.838709677 6.821 4.219 2.201 1.249 0.8506 0.21

0.870967742 6.815 4.215 2.194 1.238 0.8414 0.208

0.903225806 6.814 4.189 2.18 1.214 0.8366 0.2059

0.935483871 6.811 4.157 2.169 1.199 0.8007 0.1975

0.967741935 6.802 4.134 2.133 1.188 0.7933 0.1972

0.1 14.362 8.632 3.5283 2.0382 1.3745 0.33862

Average of 

yearly

averages: 0.249293

PCA= 100% for turf

Inputs generated by pe4.pl - 8-August2003

Data used for this run:

Output File: DW

Metfile: w12834.dvf

PRZM scenario: FLturfC.txt

EXAMS environment file: ir298.exv

Chemical Name: Cyazofamid

Description

Variable 

Name Value Units Comments

Molecular weight mwt 324.79 g/mol

Henry's Law Const. henry atm-m^3/mol

Vapor Pressure vapr 1.32E-10 torr

Solubility sol 0.107 mg/L

Kd Kd mg/L

Koc Koc 1338 mg/L

Photolysis half-life kdp 0.02 days Half-life
45

Aerobic Aquatic 

Metabolism kbacw 16.4 days Halfife

Anaerobic Aquatic 

Metabolism kbacs 17.7 days Halfife

Aerobic Soil Metabolism asm 5.5 days Halfife

Hydrolysis: pH 7 11.9 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 1.1433 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0.16 fraction of application rate applied to pond

Application Date Date 15-03 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 14 days Set to 0 or delete line for single app.

Interval 2 interval 14 days Set to 0 or delete line for single app.

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR IR

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)
46

Florida Turf (March 15) Parent without drift

stored as DW.out

Chemical: Cyazofamid

PRZM environment: 

FLturfC.txt modified Monday, 16 June 2003 at 13:48:06

EXAMS environment: 

ir298.exv modified Thuday, 29 August 2002 at 15:34:12

Metfile: w12834.dvf modified Wedday, 3 July 2002 at 09:04:28

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 0.1081 0.06651 0.01923 0.009257 0.007047 0.00177

1962 1.126 0.7223 0.2201 0.08297 0.05538 0.01366

1963 0.4841 0.3206 0.1193 0.06352 0.04323 0.01066

1964 11.15 6.928 2.263 0.8167 0.5474 0.1349

1965 1.007 0.701 0.3599 0.1285 0.08573 0.02114

1966 6.229 3.842 1.113 0.5773 0.3899 0.09625

1967 2.434 1.812 0.5655 0.2038 0.1361 0.03356

1968 1.252 0.9045 0.3645 0.1362 0.09085 0.02235

1969 1.302 0.8053 0.3352 0.1256 0.08387 0.02069

1970 1.284 0.8008 0.2353 0.09144 0.06162 0.01521

1971 2.613 1.61 0.4659 0.2275 0.1536 0.03799

1972 11.89 7.349 2.193 0.7976 0.5341 0.1314

1973 0.5983 0.3945 0.1276 0.04618 0.03105 0.007665

1974 1.241 0.7811 0.249 0.08805 0.06579 0.01652

1975 1.342 0.8251 0.2486 0.08811 0.05958 0.0147

1976 14.1 8.548 2.426 0.9584 0.6455 0.1588

1977 0.9273 0.5778 0.1716 0.06051 0.04046 0.009978

1978 13.49 8.003 2.215 0.787 0.5253 0.1295

1979 1.638 1.005 0.3548 0.1361 0.09083 0.0224

1980 0.7999 0.511 0.1477 0.08523 0.05733 0.01413

1981 0.4192 0.2511 0.06978 0.02589 0.02912 0.007449

1982 6.478 4.073 1.271 0.5031 0.3603 0.08925

1983 2.976 2.298 0.755 0.3359 0.2283 0.05639

1984 7.311 4.513 1.305 0.5009 0.3363 0.08274

1985 1.317 0.8072 0.2322 0.08826 0.05952 0.01471

1986 0.1128 0.0773 0.02332 0.008877 0.005922 0.00146

1987 6.152 3.919 1.211 0.4385 0.2928 0.07225

1988 0.07355 0.05325 0.01544 0.009152 0.00612 0.001506

1989 0.955 0.6723 0.1899 0.06694 0.04465 0.01101

1990 0.02176 0.01317 0.003968 0.001402 0.000953 0.000267

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258065 14.1 8.548 2.426 0.9584 0.6455 0.1588

0.064516129 13.49 8.003 2.263 0.8167 0.5474 0.1349

0.096774194 11.89 7.349 2.215 0.7976 0.5341 0.1314

0.129032258 11.15 6.928 2.193 0.787 0.5253 0.1295

0.161290323 7.311 4.513 1.305 0.5773 0.3899 0.09625

0.193548387 6.478 4.073 1.271 0.5031 0.3603 0.08925
47

0.225806452 6.229 3.919 1.211 0.5009 0.3363 0.08274

0.258064516 6.152 3.842 1.113 0.4385 0.2928 0.07225

0.290322581 2.976 2.298 0.755 0.3359 0.2283 0.05639

0.322580645 2.613 1.812 0.5655 0.2275 0.1536 0.03799

0.35483871 2.434 1.61 0.4659 0.2038 0.1361 0.03356

0.387096774 1.638 1.005 0.3645 0.1362 0.09085 0.0224

0.419354839 1.342 0.9045 0.3599 0.1361 0.09083 0.02235

0.451612903 1.317 0.8251 0.3548 0.1285 0.08573 0.02114

0.483870968 1.302 0.8072 0.3352 0.1256 0.08387 0.02069

0.516129032 1.284 0.8053 0.249 0.09144 0.06579 0.01652

0.548387097 1.252 0.8008 0.2486 0.08826 0.06162 0.01521

0.580645161 1.241 0.7811 0.2353 0.08811 0.05958 0.01471

0.612903226 1.126 0.7223 0.2322 0.08805 0.05952 0.0147

0.64516129 1.007 0.701 0.2201 0.08523 0.05733 0.01413

0.677419355 0.955 0.6723 0.1899 0.08297 0.05538 0.01366

0.709677419 0.9273 0.5778 0.1716 0.06694 0.04465 0.01101

0.741935484 0.7999 0.511 0.1477 0.06352 0.04323 0.01066

0.774193548 0.5983 0.3945 0.1276 0.06051 0.04046 0.009978

0.806451613 0.4841 0.3206 0.1193 0.04618 0.03105 0.007665

0.838709677 0.4192 0.2511 0.06978 0.02589 0.02912 0.007449

0.870967742 0.1128 0.0773 0.02332 0.009257 0.007047 0.00177

0.903225806 0.1081 0.06651 0.01923 0.009152 0.00612 0.001506

0.935483871 0.07355 0.05325 0.01544 0.008877 0.005922 0.00146

0.967741935 0.02176 0.01317 0.003968 0.001402 0.000953 0.000267

0.1 11.816 7.3069 2.2128 0.79654 0.53322 0.13121

Average of 

yearly

averages: 0.041677

PCA= 100% for turf

Inputs generated by pe4.pl - 8-August2003

Data used for this run:

Output File: DW

Metfile: w12834.dvf

PRZM scenario: FLturfC.txt

EXAMS environment file: ir298.exv

Chemical Name: Cyazofamid

Description

Variable 

Name Value Units Comments

Molecular weight mwt 324.79 g/mol

Henry's Law Const. henry atm-m^3/mol

Vapor Pressure vapr

1.32E10 torr

Solubility sol 0.107 mg/L

Kd Kd mg/L

Koc Koc 1338 mg/L

Photolysis half-life kdp 0.02 days Half-life

Aerobic Aquatic 

Metabolism kbacw 16.4 days Halfife
48

Anaerobic Aquatic 

Metabolism kbacs 17.7 days Halfife

Aerobic Soil Metabolism asm 5.5 days Halfife

Hydrolysis: pH 7 11.9 days Half-life

Method: CAM 2 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 1.1433 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0 fraction of application rate applied to pond

Application Date Date 15-03 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 14 days Set to 0 or delete line for single app.

Interval 2 interval 14 days Set to 0 or delete line for single app.

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR IR

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)
49

PA Turf (July 30) CCIM with drift

stored as DW.out

Chemical: CCIM

PRZM environment: 

PAturfC.txt modified Satday, 12 October 2002 at 16:27:02

EXAMS environment: 

ir298.exv modified Thuday, 29 August 2002 at 15:34:12

Metfile: w14737.dvf

modified Wedday, 3 July 2002 at 

09:06:12

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 7.485 7.357 6.871 6.045 5.662 2.096

1962 10.43 10.3 9.774 8.872 8.478 5.199

1963 12.54 12.39 11.85 10.93 10.5 7.307

1964 13.54 13.4 12.86 11.94 11.51 8.639

1965 14.36 14.26 13.72 12.77 12.32 9.473

1966 15.03 14.88 14.32 13.38 12.91 10.08

1967 15.24 15.1 14.53 13.6 13.14 10.45

1968 15.4 15.25 14.69 13.76 13.3 10.63

1969 15.54 15.39 14.83 13.9 13.43 10.77

1970 15.78 15.63 15.06 14.12 13.65 10.92

1971 19.97 19.75 18.97 17.48 16.64 12.11

1972 17.31 17.15 16.57 15.63 15.14 12.7

1973 16.8 16.64 16.07 15.13 14.65 12.12

1974 17.14 16.97 16.39 15.4 14.88 11.95

1975 16.48 16.33 15.75 14.82 14.34 11.79

1976 16.38 16.23 15.65 14.71 14.22 11.55

1977 16.14 15.99 15.42 14.49 14.02 11.42

1978 16.16 16.04 15.47 14.52 14.04 11.35

1979 15.99 15.84 15.32 14.39 13.92 11.29

1980 15.92 15.78 15.21 14.28 13.81 11.2

1981 15.86 15.71 15.14 14.21 13.75 11.13

1982 16.13 15.98 15.39 14.45 13.97 11.18

1983 15.91 15.76 15.19 14.26 13.79 11.18

1984 15.84 15.69 15.13 14.19 13.73 11.1

1985 15.97 15.82 15.24 14.31 13.83 11.11

1986 16.02 15.87 15.3 14.36 13.88 11.18

1987 16 15.85 15.35 14.43 13.96 11.23

1988 15.93 15.78 15.25 14.31 13.84 11.22

1989 15.99 15.84 15.26 14.33 13.85 11.18

1990 16.17 16.02 15.43 14.49 14 11.22

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258065 19.97 19.75 18.97 17.48 16.64 12.7

0.064516129 17.31 17.15 16.57 15.63 15.14 12.12

0.096774194 17.14 16.97 16.39 15.4 14.88 12.11

0.129032258 16.8 16.64 16.07 15.13 14.65 11.95

0.161290323 16.48 16.33 15.75 14.82 14.34 11.79

0.193548387 16.38 16.23 15.65 14.71 14.22 11.55
50

0.225806452 16.17 16.04 15.47 14.52 14.04 11.42

0.258064516 16.16 16.02 15.43 14.49 14.02 11.35

0.290322581 16.14 15.99 15.42 14.49 14 11.29

0.322580645 16.13 15.98 15.39 14.45 13.97 11.23

0.35483871 16.02 15.87 15.35 14.43 13.96 11.22

0.387096774 16 15.85 15.32 14.39 13.92 11.22

0.419354839 15.99 15.84 15.3 14.36 13.88 11.2

0.451612903 15.99 15.84 15.26 14.33 13.85 11.18

0.483870968 15.97 15.82 15.25 14.31 13.84 11.18

0.516129032 15.93 15.78 15.24 14.31 13.83 11.18

0.548387097 15.92 15.78 15.21 14.28 13.81 11.18

0.580645161 15.91 15.76 15.19 14.26 13.79 11.13

0.612903226 15.86 15.71 15.14 14.21 13.75 11.11

0.64516129 15.84 15.69 15.13 14.19 13.73 11.1

0.677419355 15.78 15.63 15.06 14.12 13.65 10.92

0.709677419 15.54 15.39 14.83 13.9 13.43 10.77

0.741935484 15.4 15.25 14.69 13.76 13.3 10.63

0.774193548 15.24 15.1 14.53 13.6 13.14 10.45

0.806451613 15.03 14.88 14.32 13.38 12.91 10.08

0.838709677 14.36 14.26 13.72 12.77 12.32 9.473

0.870967742 13.54 13.4 12.86 11.94 11.51 8.639

0.903225806 12.54 12.39 11.85 10.93 10.5 7.307

0.935483871 10.43 10.3 9.774 8.872 8.478 5.199

0.967741935 7.485 7.357 6.871 6.045 5.662 2.096

0.1 17.106 16.937 16.358 15.373 14.857 12.094

PCA= 100% for turf

Average of yearly 

averages: 10.49247

Inputs generated by pe4.pl - 8-August-2003

Data used for this run:

Output File: DW

Metfile: w14737.dvf

PRZM scenario: PAturfC.txt

EXAMS environment file: ir298.exv

Chemical Name: CCIM

Description

Variable 

Name Value Units Comments

Molecular weight mwt 217.66 g/mol

Henry's Law Const. henry atm-m^3/mol

Vapor Pressure vapr

1.32E10 torr

Solubility sol 0.107 mg/L

Kd Kd mg/L

Koc Koc 753 mg/L

Photolysis half-life kdp 31.5 days Half-life

Aerobic Aquatic 

Metabolism kbacw 0 days Halfife

Anaerobic Aquatic 

Metabolism kbacs 0 days Halfife
51

Aerobic Soil Metabolism asm 2.22 days Halfife

Hydrolysis: pH 7 0 days Half-life

Method: CAM 1 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 0.4827 kg/ha

Application Efficiency: APPEFF 0.95 fraction

Spray Drift DRFT 0.16 fraction of application rate applied to pond

Application Date Date 30-07 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 14 days Set to 0 or delete line for single app.

Interval 2 interval 14 days Set to 0 or delete line for single app.

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR IR

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)
52

OR x-mass (March 15) CCIM-AM with drift

stored as DW.out

Chemical: CCIMAM

PRZM environment: 

ORXmasTreeC.txt modified Satday, 12 October 2002 at 16:23:10

EXAMS environment: 

ir298.exv modified Thuday, 29 August 2002 at 15:34:12

Metfile: w24232.dvf modified Wedday, 3 July 2002 at 09:06:10

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 0.6695 0.6411 0.5448 0.4241 0.3796 0.2256

1962 1.122 1.084 0.9561 0.804 0.738 0.5351

1963 2.265 2.19 1.957 1.638 1.506 1.105

1964 1.801 1.773 1.677 1.558 1.513 1.359

1965 2.033 2.005 1.909 1.793 1.75 1.595

1966 2.268 2.24 2.144 2.025 1.98 1.827

1967 2.5 2.471 2.376 2.256 2.212 2.058

1968 2.731 2.703 2.607 2.488 2.443 2.289

1969 2.963 2.935 2.839 2.72 2.675 2.522

1970 3.195 3.167 3.071 2.952 2.907 2.754

1971 3.529 3.499 3.404 3.303 3.242 3.052

1972 3.731 3.703 3.618 3.498 3.455 3.297

1973 3.971 3.943 3.847 3.728 3.683 3.53

1974 4.328 4.295 4.19 4.039 3.982 3.803

1975 4.54 4.509 4.405 4.281 4.231 4.061

1976 4.767 4.738 4.637 4.511 4.464 4.303

1977 4.977 4.949 4.853 4.734 4.689 4.536

1978 5.208 5.18 5.084 4.966 4.926 4.772

1979 5.446 5.418 5.322 5.203 5.158 5.005

1980 5.677 5.649 5.592 5.47 5.423 5.257

1981 5.933 5.904 5.82 5.703 5.659 5.501

1982 6.174 6.146 6.055 5.937 5.893 5.738

1983 6.76 6.717 6.592 6.396 6.316 6.083

1984 6.763 6.735 6.664 6.552 6.506 6.342

1985 7.032 7.003 6.906 6.784 6.738 6.583

1986 7.256 7.227 7.131 7.012 6.968 6.814

1987 7.487 7.458 7.363 7.243 7.199 7.046

1988 7.724 7.696 7.599 7.479 7.434 7.278

1989 7.957 7.928 7.832 7.712 7.667 7.512

1990 8.185 8.156 8.061 7.942 7.897 7.744

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258065 8.185 8.156 8.061 7.942 7.897 7.744

0.064516129 7.957 7.928 7.832 7.712 7.667 7.512

0.096774194 7.724 7.696 7.599 7.479 7.434 7.278

0.129032258 7.487 7.458 7.363 7.243 7.199 7.046

0.161290323 7.256 7.227 7.131 7.012 6.968 6.814

0.193548387 7.032 7.003 6.906 6.784 6.738 6.583

0.225806452 6.763 6.735 6.664 6.552 6.506 6.342
53

0.258064516 6.76 6.717 6.592 6.396 6.316 6.083

0.290322581 6.174 6.146 6.055 5.937 5.893 5.738

0.322580645 5.933 5.904 5.82 5.703 5.659 5.501

0.35483871 5.677 5.649 5.592 5.47 5.423 5.257

0.387096774 5.446 5.418 5.322 5.203 5.158 5.005

0.419354839 5.208 5.18 5.084 4.966 4.926 4.772

0.451612903 4.977 4.949 4.853 4.734 4.689 4.536

0.483870968 4.767 4.738 4.637 4.511 4.464 4.303

0.516129032 4.54 4.509 4.405 4.281 4.231 4.061

0.548387097 4.328 4.295 4.19 4.039 3.982 3.803

0.580645161 3.971 3.943 3.847 3.728 3.683 3.53

0.612903226 3.731 3.703 3.618 3.498 3.455 3.297

0.64516129 3.529 3.499 3.404 3.303 3.242 3.052

0.677419355 3.195 3.167 3.071 2.952 2.907 2.754

0.709677419 2.963 2.935 2.839 2.72 2.675 2.522

0.741935484 2.731 2.703 2.607 2.488 2.443 2.289

0.774193548 2.5 2.471 2.376 2.256 2.212 2.058

0.806451613 2.268 2.24 2.144 2.025 1.98 1.827

0.838709677 2.265 2.19 1.957 1.793 1.75 1.595

0.870967742 2.033 2.005 1.909 1.638 1.513 1.359

0.903225806 1.801 1.773 1.677 1.558 1.506 1.105

0.935483871 1.122 1.084 0.9561 0.804 0.738 0.5351

0.967741935 0.6695 0.6411 0.5448 0.4241 0.3796 0.2256

0.1 7.7003 7.6722 7.5754 7.4554 7.4105 7.2548

Average of 

yearly

averages: 4.15089

PCA Adjustment (87%) 6.699 6.675 6.591 6.486 6.447 6.312

Inputs generated by pe4.pl - 8-August-2003 3.611

Data used for this run:

Output File: DW

Metfile: w24232.dvf

PRZM scenario: ORXmasTreeC.txt

EXAMS environment file: ir298.exv

Chemical Name: CCIMAM

Description

Variable

Name Value Units Comments

Molecular weight mwt 235.67 g/mol

Henry's Law Const. henry atm-m^3/mol

Vapor Pressure vapr 1.32E-10 torr

Solubility sol 0.107 mg/L

Kd Kd mg/L

Koc Koc 2397 mg/L

Photolysis half-life kdp 0 days Half-life

Aerobic Aquatic Metabolism kbacw 0 days Halfife

Anaerobic Aquatic 

Metabolism kbacs 0 days Halfife

Aerobic Soil Metabolism asm 13.58 days Halfife

Hydrolysis: pH 7 0 days Half-life
54

Method: CAM 1 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 0.1651 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.064 fraction of application rate applied to pond

Application Date Date 15-03 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 14 days Set to 0 or delete line for single app.

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR IR

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)
55

OR x-mass trees (March, 15) CTCA alone with drift

stored as DW.out

Chemical: CTCA

PRZM environment: 

ORXmasTreeC.txt modified Satday, 12 October 2002 at 16:23:10

EXAMS environment: 

ir298.exv modified Thuday, 29 August 2002 at 15:34:12

Metfile: w24232.dvf

modified Wedday, 3 July 2002 at 

09:06:10

Water segment concentrations (ppb)

Year Peak 96 hr 21 Day 60 Day 90 Day Yearly

1961 5.827 5.736 5.399 4.841 4.552 3.081

1962 15.61 15.43 14.72 14.19 13.73 10.54

1963 40.32 39.86 38.22 36.41 35.32 27.21

1964 35.21 35.12 34.79 34.24 33.96 32.62

1965 39.3 39.23 38.95 38.77 38.53 37.17

1966 44.64 44.61 44.47 43.83 43.12 41.74

1967 49.29 49.19 48.85 48.28 47.98 46.74

1968 53.29 53.2 52.87 52.51 52.42 51.09

1969 57.9 57.88 57.8 57.72 57.64 56.05

1970 63.09 63 62.67 62.12 61.84 60.47

1971 74.36 74.16 73.39 72.12 71.47 68.14

1972 75.6 75.51 75.19 74.93 74.79 73.26

1973 79.89 79.8 79.47 78.92 78.63 77.31

1974 87.39 87.24 86.69 85.78 85.31 82.99

1975 91.44 91.33 90.91 90.22 89.87 88.15

1976 95.42 95.32 94.93 94.29 93.96 92.23

1977 98.25 98.16 97.83 97.29 97.01 95.68

1978 104 104 103 103 103 101

1979 107 107 107 107 107 105

1980 114 114 114 113 113 111

1981 118 118 118 118 117 116

1982 123 123 123 122 122 120

1983 136 135 135 133 132 128

1984 137 137 136 136 136 134

1985 141 141 141 141 141 139

1986 146 146 146 145 145 143

1987 153 152 152 151 150 148

1988 157 157 157 156 156 154

1989 161 161 161 160 159 158

1990 166 166 165 165 165 163

Sorted results

Prob. Peak 96 hr 21 Day 60 Day 90 Day Yearly

0.032258065 166 166 165 165 165 163

0.064516129 161 161 161 160 159 158

0.096774194 157 157 157 156 156 154

0.129032258 153 152 152 151 150 148

0.161290323 146 146 146 145 145 143

0.193548387 141 141 141 141 141 139
56

0.225806452 137 137 136 136 136 134

0.258064516 136 135 135 133 132 128

0.290322581 123 123 123 122 122 120

0.322580645 118 118 118 118 117 116

0.35483871 114 114 114 113 113 111

0.387096774 107 107 107 107 107 105

0.419354839 104 104 103 103 103 101

0.451612903 98.25 98.16 97.83 97.29 97.01 95.68

0.483870968 95.42 95.32 94.93 94.29 93.96 92.23

0.516129032 91.44 91.33 90.91 90.22 89.87 88.15

0.548387097 87.39 87.24 86.69 85.78 85.31 82.99

0.580645161 79.89 79.8 79.47 78.92 78.63 77.31

0.612903226 75.6 75.51 75.19 74.93 74.79 73.26

0.64516129 74.36 74.16 73.39 72.12 71.47 68.14

0.677419355 63.09 63 62.67 62.12 61.84 60.47

0.709677419 57.9 57.88 57.8 57.72 57.64 56.05

0.741935484 53.29 53.2 52.87 52.51 52.42 51.09

0.774193548 49.29 49.19 48.85 48.28 47.98 46.74

0.806451613 44.64 44.61 44.47 43.83 43.12 41.74

0.838709677 40.32 39.86 38.95 38.77 38.53 37.17

0.870967742 39.3 39.23 38.22 36.41 35.32 32.62

0.903225806 35.21 35.12 34.79 34.24 33.96 27.21

0.935483871 15.61 15.43 14.72 14.19 13.73 10.54

0.967741935 5.827 5.736 5.399 4.841 4.552 3.081

0.1 156.6 156.5 156.5 155.5 155.4 153.4

Average of yearly 

averages:

88.815

7

PCA Adjusted (87%) 136.242

136.15

5

136.15

5

135.28

5 135.198

133.45

8

Inputs generated by pe4.pl - 8-August-2003 77.270

Data used for this run:

Output File: DW

Metfile: w24232.dvf

PRZM scenario: ORXmasTreeC.txt

EXAMS environment file: ir298.exv

Chemical Name: CTCA

Description

Variable 

Name Value Units Comments

Molecular weight mwt 236.66 g/mol

Henry's Law Const. henry atm-m^3/mol

Vapor Pressure vapr

1.32E10 torr

Solubility sol 1.07 mg/L

Kd Kd mg/L

Koc Koc 836 mg/L

Photolysis half-life kdp 0 days Half-life

Aerobic Aquatic Metabolism kbacw 0 days Halfife

Anaerobic Aquatic 

Metabolism kbacs 0 days Halfife
57

Aerobic Soil Metabolism asm 0 days Halfife

Hydrolysis: pH 7 0 days Half-life

Method: CAM 1 integer See PRZM manual

Incorporation Depth: DEPI 0 cm

Application Rate: TAPP 1.2751 kg/ha

Application Efficiency: APPEFF 0.99 fraction

Spray Drift DRFT 0.064 fraction of application rate applied to pond

Application Date Date 15-03 dd/mm or dd/mmm or dd-mm or dd-mmm

Interval 1 interval 14 days Set to 0 or delete line for single app.

Record 17: FILTRA

IPSCND 1

UPTKF

Record 18: PLVKRT

PLDKRT

FEXTRC 0.5

Flag for Index Res. Run IR IR

Flag for runoff calc. RUNOFF total none, monthly or total(average of entire run)
58

SCIGROW

 VERSION 2.3

 ENVIRONMENTAL FATE AND EFFECTS DIVISION

 OFFICE OF PESTICIDE PROGRAMS

 U.S. ENVIRONMENTAL PROTECTION AGENCY

 SCREENING MODEL

 FOR AQUATIC PESTICIDE EXPOSURE

SciGrow version 2.3

chemical:Cyazofamid

time is 8/28/2006 15:56:18

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

 rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------

 1.561 2.0 3.122 6.57E+02 4.7

------------------------------------------------------------------------

groundwater screening cond (ppb) = 1.18E-02 

************************************************************************

SciGrow version 2.3

chemical:CCIM

time is 8/28/2006 15:57:32

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

 rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------

 0.659 2.0 1.318 6.90E+02 1.4

------------------------------------------------------------------------

groundwater screening cond (ppb) = 6.07E-04 

************************************************************************

SciGrow version 2.3

chemical:CCIM-AM

time is 8/28/2006 15:58:38

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

 rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------

 0.147 2.0 0.294 2.12E+03 8.3

------------------------------------------------------------------------

groundwater screening cond (ppb) = 2.76E-03 

************************************************************************

SciGrow version 2.3

chemical:CTCA

time is 8/28/2006 15:59:41

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic

 rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------

 0.273 2.0 0.546 7.08E+02 10000.0

------------------------------------------------------------------------

groundwater screening cond (ppb) = 5.23E-01 

************************************************************************

SciGrow version 2.3

chemical:TotalCTCA

time is 8/28/2006 16: 0:15

------------------------------------------------------------------------

 Application Number of Total Use Koc Soil Aerobic
59

 rate (lb/acre) applications (lb/acre/yr) (ml/g) metabolism (days)

------------------------------------------------------------------------

 1.137 2.0 2.275 7.08E+02 10000.0

------------------------------------------------------------------------

groundwater screening cond (ppb) = 2.18E+00 

************************************************************************