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 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).

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, CCIM-AM 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
                                    2.18[1]
Surface water
(PRZM/ EXAMS)
Turf & Ornamentals
(3.0 & 3.12 lb a.i./A/yr, respectively)
Acute
                                    38.2[2]

Chronic
                                   133.5[1]

Cancer/Chronic
                                    77.3[1]
   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).

Use information:

There are two products that contain cyazofamid, both of which are flowable suspensions (SC): Ranman[(R)] 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[(R)] 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 planting-over 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
Succulent-Podded & Succulent-Shelled 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.  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
Value[1]
                                     MRID
Aerobic soil metabolism [2]
t(1/2) = 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

t(1/2) = 3.7-4.0 days in a Sandy loam soil from England, Soil 2 (pH 7.6, %OC= 1.2)
t(1/2) = 4.3-4.4 days in a Sandy loam soil from  England, Soil 3 (pH 6.9, %OC= 3.0)
t(1/2) = 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
t(1/2) = 4.3 d non-linear; 10.3 d linear in a Sandy loam soil from CA (pH 5.7, %OM= 0.8)
t(1/2) = 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]
 t(1/2) = 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%)
t(1/2) = 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-U-14C]:
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
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 815-1524 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<EMAIL_ADDRESS>
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)

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 parent-molar 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 (ppb)

                                     Acute
                           Chronic "Non-Cancer"
                             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 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[-7] atm*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.

   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]
                                0.054-0.078[2]
                                  6 (@ 0.071)
                                     0.426
                                       7
                            Sprinkler Irrigation[1]
                                       0
                     Grapes (East of the Rocky Mountains)
                                  0.054-0.071
                                     6[3]
                                   0.426[3]
                                      10
                                    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.

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 off-site 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).

   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.

Table 3.  Nomenclature and physicochemical properties of cyazofamid
Parameter
Value
MRID[1]
Chemical Classification
cyanoimidazole
Molecular Formula
C13H13ClN4O2S

454090-38
Chemical Name (IUPAC)
4-chloro-2cyano-N,N-dimethyl-5-p-tolylimidazole-1-sulfonamide

Chemical Name (CAS)
4-Chloro-2-cyano-N,N-dimethyl-5-(4-methylphenyl)-1H-imidazole-1-sulfonamide
Cyazofamid 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 (25[o]C)
<1.33 x10[-5] Pa or <9.9810[-8] mmHg or <1.32x10[-10] atm.
EPA Fact sheet
Henry's Law Constant
<4.0x10[-7] atm. m[3] 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
Value[1]
                                     MRID
Hydrolysis
t(1/2) ~ 11.9 days @ 25[o]C, pH 4
t(1/2) ~12.9 days @ 25[o]C, pH 5
t(1/2) ~ 11.9 days @ 25[o]C, pH 7
t(1/2) ~10.8 days @ 25[o]C, pH 9
t(1/2) ~ 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
t(1/2) ~ 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 [benzene-[14]C] cyazofamid.

                                   454091-02
                                   465377-03
                                   467027-03
Photolysis on soil
t(1/2) ~ 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]
t(1/2) = 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

t(1/2) = 3.7-4.0 days in a Sandy loam soil from England, Soil 2 (pH 7.6, %OC= 1.2)
t(1/2) = 4.3-4.4 days in a Sandy loam soil from  England, Soil 3 (pH 6.9, %OC= 3.0)
t(1/2) = 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]
t(1/2) = 14.7- 18.0 days (total system): River water/Sandy loam (~3:1)
t(1/2) =   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]
 t(1/2) = 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-U-14C]:
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, CCIM-AM 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 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 (t(1/2) for [phenyl-U-[14]C] - t(1/2) for [imidazole-4-[14]C]
                                    MRID ()

                                     CCIM
                                    CCIM-AM
                                     CTCA

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
 t(1/2) = 1.9[2] - 1.3 days
t(1/2) =  6.3 - 6.6 days

t(1/2) >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
t(1/2) = 1.3 - 0.9 days
t(1/2) =   10.0 - 6.6 days

Soil 5
t(1/2) =  2.9 - 2.6 days
t(1/2) = 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:
[Benzene-U-[14]C]
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, 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-life[1]
                                     Soil
Dissipation of Cyazofamid and its Degradation Products
Grant County, WA
454091-16 (O)
465377-17 (R)
465524-02 (A)
                               t(1/2) =  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)
                                 t(1/2) =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)
                                t(1/2) =  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)
                                t(1/2) = 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
                                   t(1/2) 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
                                   t(1/2) 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] t(1/2) = 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 half-lives 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 un-characterized 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 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. <IP_ADDRESS>, 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 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.

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
                                   Value[1]
Reference
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 90[th] percentile t(1/2) 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 90[th] percentile t(1/2) 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-life (days)
(Anaerobic Aquatic Metabolism half-life)
                                    Parent
                                     17.7
One half-life value; 3x5.9=17.7 (MRID 454091-09)

                                  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
Maximum dark control corrected value (MRID 454091-02)

                                     CCIM
                                     31.5

                               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.

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 t(1/2) (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 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
Output from SCI-GROW model runs

2[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 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 vegetables and 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 represented[1], 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 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 (90[th] 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 half-lives 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.

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; non-cancer 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.

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

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
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-imidizole-1-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.

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.

CTCA

IUPAC Name:
4-Chloro-5-p-tolylimidazole-2-carboxylic acid.
CAS Name:
Not reported.
CAS Number:
Not reported.

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
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)

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
 ************************************************************************

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

(1) 1[st] 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) 3[rd] 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 EDWC (ppb)

                                     Acute
                           Chronic "none-Cancer"
                             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" + CCIM-AM "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 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, CCIM-AM 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** (lb a.i./Acre for turf)

                                     Value
                                Adjusted Value
                                Fate Study Used

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 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 Half-life (days)
                                    Parent
                                      5.5
The 90[th] percentile t(1/2) 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

Water column Half-life (days)
(Aerobic Aquatic Metabolism half-life)
                                    Parent
                                     16.4
The 90[th] percentile t(1/2) 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 half-life)
                                    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 the top 4 cm)

                                  Degradates
                                      7.5

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 Half-life @ 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 Half-life(days)
                                    Parent
                                     0.02
Maximum dark control corrected value (MRID 454091-02)

                                     CCIM
                                     31.5

                                  Degradates
                                    Stable
No data

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
                                      0%

OR x-mass 03/15)
(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