Document ID: EPA-HQ-OPP-2015-0263-0008
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2016-02-03T05:00Z

OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION
                 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                            WASHINGTON, D.C.  20460
              OFFICE OF CHEMICAL SAFETY
AND POLLUTION PREVENTION
                 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                            WASHINGTON, D.C.  20460

MEMORANDUM				

DATE:	October 6, 2015
	
SUBJECT:	Estimated Drinking Water Concentrations of Cyazofamid and its Degradates of Concern CCIM, CCIM-AM and CTCA, for Use in Human Health Risk Assessment: Petitions for the Use on Herb (Subgroup 19A), Greenhouse Tomato, Greenhouse Pepper, and Bulb Vegetables (Group 03-07)
		(PC Code 085651; DP Barcode D426776)

TO:		Laura Nollen, Chemical Review Manager
		Barbara Madden, Minor Use Team Leader
		Marion Johnson, Branch Chief
		Risk Integration, Minor Use and Emergency Response Branch

		Lindsay Roe, Chemical Review Manager
		Tony Kish, Product Manager #22
		Cynthia Giles-Parker, Branch Chief
		Fungicide Branch
		Registration Division (7505P)

AND:		Cassi Walls, Risk Assessor
		Charles Smith, Branch Chief
		Registration Action Branch 1
		Health Effects Division (7509P)

FROM:	José Meléndez, Chemist
		Environmental Risk Branch 5
		Environmental Fate and Effects Division (7507P)

THROUGH:	Mah T. Shamim, Ph.D., Branch Chief
		Environmental Risk Branch 5
		Environmental Fate and Effects Division (7507P)

   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.  Requests for registration of several new crops were submitted to the Agency, including Herb (Subgroup 19A), greenhouse tomato, greenhouse pepper, and use on Bulb Vegetables (Group 03-07).  Based on a review of the use information, it was found that the proposed new crops have much lower seasonal application rates than previously assessed turf and ornamentals.  The highest seasonal rates among the newly proposed crops belong to the Herb Subgroup 19A (which includes the previously evaluated specific crop basil) at ~0.7 lb a.i./A/ season, compared to 3.0  -  3.12 lb a.i./A/season for turf and ornamentals (Table 2).  Surface water EDWCs for the new uses should be smaller than those already calculated for turf and ornamentals; the surface water values reported in the previous assessment can be used to cover the new crops.  However, for groundwater, new EDWCs using the new model PRZM-GW were calculated in the current Drinking Water Assessment (DWA) (Appendix A).
   
   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 of concern in water and should be included in the drinking waters assessment (Acierto et al. 2004, DP Barcode D298915).
   
   As summarized in Table 1, the surface water acute EDWC is 38.2 ppb of cyazofamid plus the degradates CCIM and CCIM-AM (for further details, refer to the previous DWA).  The surface water non-cancer chronic value is 133.5 ppb of CTCA and the cancer/chronic EDWC is 77.3 ppb of CTCA.  The above stated values represent upper-bound estimates of the parent and degradates' concentrations that might be found in surface water due to the use of cyazofamid on turf and ornamentals, as reported previously in DP Barcodes D319466 and D356839.  The maximum value for ground water is 224 ppb of CTCA for acute exposure and 211 ppb of CTCA for chronic exposure, resulting from the WI sand scenario (for further details, refer to the Appendix A).   It should be noted that these are still screening-level values and further refinements may be conducted.  Should any questions arise, please, contact EFED.

Table 1.  Maximum Estimated Drinking Water Concentrations for Cyazofamid, CCIM, CCIM-AM and CTCA.  Maximum EDWCs Are Based on the Use on Turf and Ornamentals
Drinking Water Source (Model Used) 
Use (rate modeled per year)
Estimated Drinking Water Concentration  (EDWC)  (ppb) (Species) 
Groundwater
(PRZM-GW)
Ornamentals (3.12 lb a.i./A/yr)
Acute (CTCA)
                                    224[1]

Chronic (CTCA)
                                    211[1]
Surface water
(PRZM/EXAMS)
Turf & Ornamentals
(3.0 & 3.12 lb a.i./A/yr, respectively)
Acute (cyazofamid, CCIM, CCIM-AM)
                                    38.2[2]

Chronic (CTCA)
                                   133.5[2]

Cancer/Chronic (CTCA)
                                    77.3[2]
 For groundwater, acute and chronic exposure is based on modeling the degradate CTCA.
 For surface water, acute exposure is based on modeling of the parent cyazofamid plus the degradates CCIM and CCIM-AM.  Chronic exposure is based on modeling of the degradate CTCA.

   For surface water, a previous DWA, dated March 24, 2009 (DP Barcode D356836), provides structures and nomenclature of cyazofamid and its transformation products.  Moreover, a DWA dated September 6, 2006 (DP Barcode D319466), provides maximum surface waters (PRZM/EXAMS) EDWCs; in the 2006 assessment, turf and ornamentals were modeled.  These previous DWAs provide specific information about the chemicals modeled (cyazofamid, CCIM, CCIM-AM, and CTCA), structures, problem formulation and approach taken in modeling the crops, a summary of physicochemical and environmental fate properties of the chemicals, etc.  Additional details about the environmental fate database for cyazofamid can be found in the Problem Formulation for Registration Review of Cyazofamid (DP Barcode: D422930; March 16, 2015).  EFED calculated new groundwater EDWCs in the current DWA, which are provided in the Appendix A.  At the present time, EFED did not evaluate the greenhouse uses of cyazofamid, since it is believed usage will be low; however, should additional greenhouse uses, besides tomatoes and peppers be added to the label, the Division may need to revisit the issue.
   
Use information:
   
   There are two products that contain cyazofamid, both of which are flowable suspension concentrates (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 2).  Requests for registration of new crops were submitted to the Agency, including Herb Subgroup 19A, greenhouse tomato, greenhouse pepper, and use on Bulb Vegetables Group 03-07.  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 maximum seasonal rates for the new crops range from 0.43 lb a.i./A/season for Bulb Vegetables Group 03-07, to ~0.7 lb a.i./A/season for Herb Subgroup 19A.  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 3 and 2 applications, respectively (Table 2).
   
Table 2. Summary of use information for cyazofamid, based on the current and proposed labels 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 new crops are shaded BLUE.
                                      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)
Bulb Vegetables, Crop Group 3-07 (daylily, bulb; elegans hosta; fritillaria, bulb and leaves; garlic, bulb; garlic, great-headed, bulb; garlic, serpent, bulb; kurrat; lady's leek; leek; leek, wild; lily, bulb; onion, Beltsville bunching; onion, bulb; onion, Chinese, bulb; onion, fresh; onion, green; onion, macrostem; onion, pearl; onion, potato, bulb; onion, tree, tops; onion, Welsh, tops; shallot, bulb; shallot, fresh leaves; cultivars, varieties, and/or hybrids of these)
                                  0.071-0.078
                                       6
                                     0.43
                                       7
                         Foliar, sprinkler irrigation
                                       0
Herb Group, Crop Subgroup 19A
(Basil[1], angelica, balm, borage, burnet, chamomile, catnip, chervil (dried), chive, Chinese chive, clary, coriander leaf (Chinese parsley), costmary, cilantro (leaf), curry (leaf), dillweed, horehound, hyssop, lavender, lemongrass, lovage (leaf), marigold, marjoram (includes sweet and annual marjoram, wild marjoram or oregano, and pot marjoram), nasturtium, parsley (dried), pennyroyal, rosemary, rue, sage, summer and winter savory, sweet bay, tansy, tarragon, thyme, wintergreen, woodruff, and wormwood)
                                  0.071-0.078
                                       9
                                      0.7
                                       7
  Foliar, sprinkler irrigation, can be applied on herbs grown in greenhouses
                                       0
Greenhouse Grown Bell Peppers
                         0.083 lb a.i./ 100 gal water;
                                    ------
     1[st] app 5 fl oz solution/plant; 2[nd] app 8.5 fl oz solution/ plant
                                       2
                     13.5 fl oz solution/ plant/crop cycle
                                      42
                                  Soil drench
                                       0
Tomato Greenhouse Transplants
                         0.078 lb a.i./ 100 gal water;
                                    ------
                            ~1 pint solution/ft[2]
                                      NS
                                      NS
    As needed, starting from planting up until 1 week before transplanting
                                  Soil drench
                                       0
Fruiting Vegetables, Crop Group 8-10 [tomato (field grown and greenhouse grown), ground cherry, tomatillo, bell pepper, cooking pepper, pimento, sweet pepper, 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
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
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
G=ground; A=aerial
[1] Basil is a crop that was previously registered, but it belongs to the Crop Subgroup 19A.

Identification of specific data gaps:

After the submission of several new studies, it was found that the environmental fate database for cyazofamid is nearly complete.  Additional details about the environmental fate database for cyazofamid can be found in the Problem Formulation for Registration Review of Cyazofamid (DP Barcode: D422930; March 16, 2015, and available at: http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2015-0128-0005).  Environmental Chemistry Methods/Independent Laboratory Validations (OCSPP 850.6100), in soil, water and sediment, should be made available.  It should be noted that the ECMs/ILVs' results are not used to derive any of the input parameters for surface or ground water EDWCs.
Appendix A. Tier 1 EDWCs for Groundwater Using PRZM-GW

PRZM-GW v.1.07

Summary
   
   The maximum value for ground water is 224 ppb of CTCA for acute exposure and 211 ppb of CTCA for chronic exposure, associated with the Wisconsin sand scenario.  There is a potential for these EDWCs to be higher, if the degradation of CTCA in the sandy soil is considered to be persistent in lieu of 365 days.
   
Conceptual Model
   
   Figure A-1 depicts the general groundwater scenario concept for estimating pesticide concentrations in drinking water as implemented in PRZM-GW. This conceptual model is based on a rural drinking water well beneath an agricultural field (a high pesticide use area) drawing from an unconfined, high water-table aquifer. 
   
                                       
 
Figure A-1. General Groundwater Scenario Concept for Estimating Pesticide Concentrations in Drinking Water as Implemented in PRZM-GW; The black line through the soil profile represents the decline in degradation with respect to the depth.
   
   The depth of the well is site specific (i.e., scenario specific). The well extends into a shallow unconfined aquifer and has a well-screen that starts at the top and extends down into the aquifer. The length of the well-screen represents the region of the aquifer where drinking water is collected. The well-screen length is well-specific and can be adjusted. Processes included in the conceptual model that influence pesticide transport through the soil profile include water flow, chemical specific dissipation and transportation parameters (i.e., degradation and sorption), and crop specific factors, including transpiration, pesticide interception and management practices.
   
   The following is a brief description of the PRZM-GW model.  More information is available at http://www.epa.gov/oppefed1/models/water/ (accessed 06/25/2015).
   
  Tier 1 groundwater estimated drinking water concentrations (EDWCs) for a chemical, resulting from its use on a crop are derived with PRZM-GW (Pesticide Root Zone Model for Groundwater, version 1.07, March 6, 2014), using the GW-GUI (Graphical User Interface, version 1.07, March 6, 2014).  PRZM-GW is a one-dimensional, finite-difference model that estimates the concentrations of pesticides in groundwater.  It accounts for pesticide fate in the crop root zone by simulating pesticide transport and degradation through the soil profile after a pesticide is applied to an agricultural field. PRZM-GW permits the assessment of multiple years of pesticide application (up to 100 years) on a single site.  Six standard scenarios, each representing a different region known to be vulnerable to groundwater contaminations, are available for use with PRZM-GW for risk assessment purposes.  In PRZM-GW simulations, each of these standard scenarios is used.  PRZM-GW output values represent pesticide concentrations in a vulnerable groundwater supply that is located directly beneath a rural agricultural field.

Input Parameters for PRZM-GW and Results
   
   Given that groundwater exposure occurs usually after a long period of time, the terminal degradate of cyazofamid was modeled in lieu of the parent cyazofamid.  It was assumed 100% CTCA formation from the parent compound.  The crop leading to maximum exposure is ornamentals, with an application rate of 1.56 lb a.i./A (2 applications allowed at 14-day intervals).  This corresponds to an application rate of 1.137 lb CTCA/acre.  For input parameters used in this groundwater model, refer to Table A-1.

Table A-1. PRZM-GW Input Parameters for modeling ground applications of CTCA, a degradate of cyazofamid, on ornamentals
                               PARAMETER (units)
                                   VALUE[1]
                                    SOURCE
                                    COMMENT
Application date (day/month)
                                     01-05
Label does not specify timing of applications.  Applications are set to occur between crop emergence and harvest.
Delmarva emergence 10-04, crop maturation 30-05, harvest 15-06

                                     01-04
                                       
FL citrus crop emergence 01-01, crop maturation 01-02, harvest 31-12

                                     01-04
                                       
FL potatoes emergence 15-02, crop maturation 01-05, harvest 01-06

                                     01-06
                                       
GA coast emergence 01-05, crop maturation 01-08, harvest 01-10

                                     01-06
                                       
NC coast emergence 15-05, crop maturation 01-08, harvest 01-11

                                     01-06
                                       
WI sand emergence 01-05, crop maturation 21-07, harvest 20-10
Maximum Application Rate (kg a.i./ha)
                                     1.274
                                     Label
Maximum rate allowed is 1.56 lb a.i./A x 2 applications at 14 day interval.  100% conversion of parent to CTCA is assumed.  The molar conversion factor is 236.66/324.79 = 0.7287.  Applying the conversion factor the maximum rate is 1.137 lb CTCA/A, or 1.274 kg CTCA/ha.
Number of Applications per Year
                                       2
                                       

Retreatment Intervals (days)
                                      14
                                       

Chemical Application Method (CAM)
                                       2
                                     Label
Foliar
Incorporation Depth (cm)
                                       0
                                     Label
Apply cyazofamid by ground equipment, soil drench, soil surface spray, or chemigation applications to ornamentals.
Air diffusion coefficient (cm[2]/day)
                                       0
                                      N/A
Assuming no volatilization.
Vaporization enthalpy (kcal/mol)
                                       0
                                      N/A
Assuming no volatilization.
Henry's Law Constant (atm-m[3]/mol)
                                       0
                                      N/A
Assuming no volatilization.
Partition Coefficient (KOC; mL/gOC)
                                      836
                                   45409114,
                                   46537714
Sorption is correlated with organic carbon.  Mean value out of four available soil values.
Aerobic Soil Metabolism Half-life (days)

                                     288.2
                                   45409105,
                                   46537710
PestDF half-lives are as follows at 20°C:
208 days (SFO) in UK sandy loam, 359 days (SFO) in UK loamy sand, and 365 (SFO) in German sand.
90% upper confidence limits on the mean for the following corrected half-life values at 25°C: 147 days (SFO), 254 days (SFO) & 258 (SFO), respectively.  Mean = 219.67 days; standard deviation = 62.96 days; n = 3; t90, n-1 = 1.886.
Hydrolysis Half-life (days)
                                       0
                                   45409101,
                                   46537702,
                                   46702702
Stable at 50ºC for 5 days in pHs 4, 7, and 9 buffered solutions.
1 Parameters are selected as per "Guidance for Selecting Input Parameters for Modeling Pesticide Concentrations in Groundwater Using the Pesticide Root Zone Model" v.1.0, dated October 15, 2012.
   
   For three of the scenarios: FL potatoes, GA coast, and WI sand, extended weather files were required, since breakthrough was incomplete after 30 years.  Results are provided in Table A-2.

Table A-2. Estimated Drinking Water Concentrations (EDWCs) of CTCA, a degradate of cyazofamid, resulting from the use on ornamentals
                                 Crop/Scenario
                              Highest Daily Value
                                    (ug/L)
                           Post Breakthrough Average
                                    (ug/L)
                     Average Simulation Breakthrough Time
                                    (days)
                          Ornamentals/Tier I Delmarva
                                     44.9
                                     44.6
                                    10,913
                         Ornamentals/Tier I FL citrus
                                      114
                                      113
                                     9,130
                        Ornamentals/Tier I FL potatoes
                                     0.28
                                  Incomplete
                                  Incomplete
          Ornamentals/Tier I FL potatoes, with extended weather file
                                     0.371
                                     0.33
                                    18,838
                          Ornamentals/Tier I GA coast
                                     3.83
                                  Incomplete
                                  Incomplete
            Ornamentals/Tier I GA coast with extended weather file
                                     31.1
                                     28.9
                                    15,032
                          Ornamentals/Tier I NC coast
                                     62.1
                                     60.7
                                     9,688
                          Ornamentals/Tier I WI sand
                                     51.9
                                  Incomplete
                                  Incomplete
             Ornamentals/Tier I WI sand with extended weather file
                                      224
                                      211
                                    13,561
Bolded values represent the maximum EDWCs.

Example Output File from PRZM-GW

Groundwater Analysis for CTCA and the Florida Citrus - FL Central Ridge, Polk County - (Tampa) Met File (12842.Dvf) - Astatula Sand, Hrgb A Scenario

Estimated groundwater concentrations and breakthrough times for CTCA are presented in Table 1 for the Florida Citrus - FL Central Ridge, Polk County - (Tampa) Met File (12842.dvf) - Astatula sand, hrgb A groundwater scenario. A graphical presentation of the daily concentrations in the aquifer is presented in Figure 1. These values were generated with the PRZM-GW (Version 1.07). Critical input values for the model are summarized in Tables 2 and 3.

Table 1. Groundwater Results for CTCA and the Florida Citrus - FL Central Ridge, Polk County - (Tampa) Met File (12842.dvf) - Astatula sand, hrgb A Scenario.
Peak Concentration (ppb)
     114
Post-Breakthrough Mean Concentration (ppb)
     113
Entire Simulation Mean Concentration (ppb)
    53.1
Average Breakthrough Time (days)
9129.938
Throughputs
1.200446

Table 2. Chemical Properties for Groundwater Modeling of CTCA.
Koc (ml/g)
836
Surface Soil Half Life (days)
288.2
Hydrolysis Half Life (days)
0
Diffusion Coefficint Air (cm2/day)
0.0
Henry's Constant
0.0
Enthalpy (kcal/mol)
0.0

Table 3. Pesticide application scheme used for CTCA.  This application scheme was applied every year of the simulation.
Application Date
(Month/Day)
Application Method
Application Rate
(kg/ha)
04/01
Above canopy application
1.274
04/15
Above canopy application
1.274

Figure 1. Aquifer Breakthrough Curve for CTCA and the Florida Citrus - FL Central Ridge, Polk County - (Tampa) Met File (12842.Dvf) - Astatula Sand, Hrgb A Scenario