Document ID: EPA-HQ-OPP-2012-0009-0015
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2012-11-07T05:00Z

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

MEMORANDUM

DATE:	July 17, 2012

SUBJECT:	Tier I Estimated Drinking Waters Concentrations of Fluazinam and its Transformation Products for the Use in the Human Health Risk Assessment for the Registration of the New Uses on Peppers, Eggplant (Subgroup 8-10B), Melons (Subgroup 9A), and Soybeans
            (PC Code 129098; DP Barcodes D397602, D402576)

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

THROUGH:	Mah T. Shamim, Ph.D., Chief
		Environmental Risk Branch 5
		Environmental Fate and Effects Division (7507P)
		
TO:	Tawanda Maignan, Risk Manager Reviewer
		Tony Kish, Review Manager #22
		Cynthia Giles-Parker, Chief
		Fungicide Branch

		Andrew Ertman, Risk Manager Reviewer
		Barbara Madden, Review Manager #05
		Dan Rosenblatt, Chief
      Risk Integration, Minor Use and Emergency Response Branch
		Registration Division (7505P)

		Douglas Dotson, Ph.D., Chemist
      Christina Swartz, Chief
      Registration Action Branch 2
		Health Effects Division (7509P)

This memorandum presents the Estimated Drinking Water Concentrations (EDWCs) for the pyridine fungicide fluazinam, and for its major transformation products DCPA, HYPA, CAPA, DAPA and AMPA, for use in the human health risk assessment.  An IR-4 request for registration of various new crops was submitted to the Agency.  These included the Cucurbits (Melons) Subgroup 9A and the Peppers/Eggplant Fruiting Vegetables Subgroup 8-10B.  Furthermore, the registrant submitted application for the use on soybeans under Section 3 registration.  Based on a review of the use information, it was found that the proposed new crops have a lower seasonal application rates than the previously evaluated uses on turf.  The maximum seasonal rates for the newly proposed crops is 4.68 lb a.i./A, compared to 8.4 lb a.i./A/season for turf (DP Barcode D391184) (Table 1-2).  EDWCs for the new uses should be smaller than those already calculated for turf; therefore, a new drinking water assessment (DWA) is not required.  The values reported in the previous assessment can be used to cover the new crops.

The last DWA is dated August 3, 2011 (assessment of the use on turf; DP Barcode D391184).  The same DWA has a copy of the DWA dated February 24, 2010 appended (uses on lettuce, apples, carrots and bulb vegetables, Crop Subgroup 3-07A; DP Barcodes D360713, D365942 & D365948).  This DWA and attachment provide specific information about the chemicals modeled (fluazinam, DCPA, HYPA, CAPA, DAPA and AMPA), structures, problem formulation and approach taken in modeling the crops, a summary of physicochemical and environmental fate properties of the chemicals, previous agricultural and turf uses, mode of action, analysis, uncertainties, characterization, etc.
EDWCs were calculated for total fluazinam residues because the environmental fate studies indicated that the parent compound undergoes transformation to compounds with a similar structure to the parent under most conditions [as per the Metabolism Assessment Review Committee (MARC) request, DP Barcode D272624, W. Cutchin, 04/23/2001].

The EDWCs summarized in Table 1-1 represent upper-bound estimates of the parent and degradates' concentrations that might be found in surface water and groundwater due to the use of fluazinam on turf, as reported previously in DP Barcode D391184.   It is noted that this is still a screening-level analysis and refinements are possible.  Should any questions arise, please, contact the Environmental Fate and Effects Division (EFED).

Table 1-1.  Maximum Tier 1 Estimated Drinking Water Concentrations (EDWCs) for drinking water assessment based on ground application of fluazinam on turf at a seasonal rate of 8.4 lb a.i./A
                                 Source/Model
                                   Fluazinam
                        Total Residues of Fluazinam[1]
                                       
                                   Acute/ppb
                                  Chronic/ppb
                                   Acute/ppb
                                  Chronic/ppb
                             Surface Waters/FIRST
                                     217 2
                                     1.47
                                     226 2
                                     37.8
                             Groundwater/SCI-GROW
                                     0.404
1. Including the following transformation products: DCPA, HYPA, CAPA, DAPA and AMPA.
[2][.] Exceeds the solubility of fluazinam at pH 7 (71 ppb), but not the solubility at pH 11 (350 ppm).

Background and New Use Information

As indicated above, new uses for fluazinam have been requested by the IR-4 Project and the registrant, ISK Biosciences Corporation, under Section 3, on cucurbits (melons), fruiting vegetables (peppers/eggplant), and soybeans (Table 1-2).  It was found that the maximum seasonal application rate for the previously assessed use on turf (8.4 lb a.i./A/season) is much higher than for the new uses (4.68 lb a.i./A/season).

A summary table of the newly proposed use patterns is provided in Table 1-2.  This information is based on the proposed Supplemental Labels for the product OMEGA[(R)] 500F (EPA Reg. No. 71512-1), which contains 40.0% a.i. or 4.17 lb a.i./gal of product.  The product label claims that it is a broad spectrum fungicide for use to control diseases such as Downy Mildew, Alternaria Leaf Spot and Gummy Stem on cucurbit (melon) crops, Phytophthora blight (Phytophthora capsici) on peppers/eggplant, and white mold (Sclerotinia Sclerotiorum) on soybeans.

Table 1-2.  Use information for fluazinam based on proposed Supplemental Labels for OMEGA[(R)] 500F (EPA Reg. No. 71512-1)
                                      USE
               MAX. SINGLE  APP. RATE              (lb. a.i./A)
                         NUMBER OF APPS. AT MAX. RATE
                        SEASONAL APP. RATE (lb. a.i./A)
                     MINIMUM INTERVAL BETWEEN APPS. (days)
                                  APP. METHOD
                                      PHI
                                    (days)
Cucurbit Vegetables, Melon Subgroup 9A; Includes Citron melon; Muskmelon, including hybrids and/or varieties of Cucumis melo (including true cantaloupe, cantaloupe, casaba, Santa Claus melon, Crenshaw melon, honeydew melon, honey balls, Persian melon, golden pershaw melon, mango melon, pineapple melon, snake melon); and watermelon, including hybrids and/or varieties of Citrullus spp.
                                     0.78
                                       6
                                     4.68
                                       7
                                   Foliar[1]
                                      30
Fruiting Vegetable, Pepper/ Eggplant Subgroup 8-10B; Includes African eggplant; bell pepper; eggplant; martynia; nonbell pepper; okra; pea; eggplant; pepino; roselle; scarlet eggplant; cultivars, varieties, and/ or hybrids of these
                                     0.78
                                       6
                                     4.68
                                       7
                                  Foliar[1,2]
                                      30
Soybeans
                                     0.52
                                       2
                                     1.04
                                      10
                                    Foliar
                                     NS[3]
[1] Use sufficient water to provide coverage of foliage.  Aerial applications are not allowed for these crops.  May be applied through sprinkler system irrigation equipment.
2 The initial application may be made as a soil drench at transplanting.
[3] Do not apply after growth stage R3, early pod formation.

Data Gaps

In previous reviews, it was indicated that the environmental fate database for fluazinam is substantially complete.  It was stated that the terrestrial field dissipation and environmental chemistry methods/independent laboratory validations (ECMs/ILVs) were environmental fate data gaps.  ISK Biosciences Corporation has submitted several studies which are currently being reviewed.  They will be evaluated and their suitability determined.

835.6100: Terrestrial Field Dissipation.  Three terrestrial field dissipation studies were submitted (MRID#s 48361521, 48361522 & 48361523).  Another relevant study includes a storage stability study (MRID# 48361518).

835.6100, 835.6200:  Environmental Chemistry Methods (ECMs) and Independent Laboratory Validations (ILVs) for Soil, Water and Sediment.  The registrant submitted various method and validation studies (MRID#s 48361519, 48361520, 48361524, 48632401, 48632402, 48635801 & 48635802).

Finally, the registrant submitted a study which had not been previously required (MRID# 48361525).  Despite being identified by guideline number as an aquatic field dissipation study in the transmittal letter, it is an aerobic aquatic metabolism study.