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








MEMORANDUM

DATE:	October 12, 2012

SUBJECT:	Tier 1 Drinking Waters Analysis for the Proposed New Uses of Sodium 1-Naphthalene-acetate, and Ethyl 1- Naphthaleneacetate, on Rambutan, Avocado, Mamey Sapote and Mango, and Inclusion of Pome Fruits Group 11-10 (PC Codes 056002, 056007, 056008; DP Barcode D399622)

TO:		Rosemary Kearns, Risk Manager Reviewer
			Tony Kish, Risk Manager #22
			Cynthia Giles-Parker, Chief
			Fungicide Branch

			Laura Nollen, Risk Manager Reviewer
            Barbara Madden, Risk Manager, Risk Manager #05
            Luis Suguiyama, Acting Chief
            Risk Integration, Minor Use and Emergency Response Branch
		Registration Division (7505P)

AND:			Sue Hummel, Risk Assessor
			Thurston Morton, Dietary Assessor
			Elissa Reaves, Chief
			Risk Assessment Branch IV
			Health Effects Division (7509P)

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

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

This memo presents the Tier I Estimated Surface Drinking Water Concentrations and Estimated Ground Drinking Water Concentrations (EDWCs) for 1-naphthaleneacetic acid and its associated compounds sodium 1-naphthaleneacetate (Na-NAA) and ethyl 1-naphthaleneacetate (EE-NAA), calculated using the Tier 1 aquatic models FIRST and SCI-GROW, respectively, for use in the human health risk assessment.

The Interregional Research Project No. 4 (IR-4) and the registrant, AMVAC Chemical Corporation, petitioned a tolerance exemption for the above mentioned chemicals for the products Tre-Hold[(R)] Sprout Inhibitor A-112, and Fruitone[(R)] L.  The Environmental Fate and Effects Division (EFED) has reviewed the proposed new uses on rambutan, avocado, mamey sapote and mango at a maximum seasonal rate of 0.22 lb a.e/A and 0.11 lb a.e. for rambutan.  Based on an inspection of the new uses of NAA related compounds, it was found that the crop olives still represents the scenario with the highest exposure and consequently the highest EDWCs (with an application rate of 0.33 lb a.e./A/application in a single application per season; DP Barcode D387171).  Therefore, the drinking waters assessment results do not change from the previous ones.  The previous DWA has the nomenclature and structures of NAA and its associated compounds.  For a summary of the results, see Table 1.  Should it be required by HED, the EFED may explore whether additional refinements of the assessment can be developed or higher tier analysis may be performed.  Should any questions arise related to this DWA, please contact EFED as soon as possible.

Table 1.  Maximum Tier I Estimated Drinking Water Concentrations (EDWCs) for drinking water assessment based on airblast application of 1-naphthalene acetic acid and/or related compounds (collectively known as naphthalene acetates) on olives
DRINKING WATER SOURCE (MODEL USED) 
                       USE (rate modeled per crop cycle)
MAXIMUM ESTIMATED DRINKING WATER CONCENTRATION  (EDWC)  ( ppb) 
Groundwater (SCI-GROW)
                            Olives (0.33 lb a.e./A)
Acute and Chronic
                                    0.0226
Surface water  (FIRST)
                            Olives (0.33 lb a.e./A)
Acute
                                     22.3

                            Olives (0.33 lb a.e./A)
Chronic
                                     2.99


Identification of specific data gaps:

Very little environmental fate data were available for these compounds.  Quantitative structure activity relationships (QSAR) and limited available data were used to derive some of the input parameters for the models.  The major uncertainties with respect to this assessment are related to the absence of measured values for fate parameters.  Furthermore, there is lack of information about possible degradates of NAA.

Use Characterization

A summary table of all use patterns for NAA is provided in Table 2.  The proposed new uses are shaded blue, while the modeled use is bolded and underlined.


Table 2.  Summary use information for naphthalene acetates, based on the 2007 revision of the RED, the label for Rejuvenate Seed Treatment, and the proposed labels for Tre-Hold[(R)] Sprout Inhibitor A-112, and Fruitone[(R)] L.  The proposed new uses are shaded blue.  The modeled use is bolded and underlined.
                                      USE
                               SINGLE  APP. RATE
                                 (lb. a.e./A)
                                NUMBER OF APPS.
                        SEASONAL APP. RATE (lb. a.e./A)
                         INTERVAL BETWEEN APPS. (days)
                                APP. METHOD[*]
                            INCORP. DEPTH (inches)
Rambutan
                                     0.11
                                       1
                                   0.11[##]
                                       5
                                       T
                                       0
Avocado, mamey sapote, mango
                                     0.11
                                       2
                                     0.22
                                      45
                                    G, A, B
                                       0
CG 11-10 Pome fruits: Apples, pears[**], azarole, crabapple, loquat, mayhaw, medlar, Asian pear, quince, Chinese quince, Japanese quince, Japanese quince, tejocote and cultivars, varieties and/or hybrids of these
                                     0.11
                                       3
                                     0.33
                                       5
                                   G, A, SD
                                       0
Citrus (mandarin, oranges, tangelos, tangerines, and non-bearing), cherries, some non-bearing fruit and nut trees, ornamental plants (herbaceous, non-flowering trees, woody shrubs and vines), shade trees, and residential fruit, and ornamental trees
                                     0.11
                                       3
                                     0.33
                                       5
                                   G, A, SD
                                       0
Olives
                                     0.33
                                       1
                                     0.33
                                      N/A
                                      AB
                                       0
Potato seed pieces
                                    0.0004
                                       1
                                    0.0004
                                      N/A
                                      ST
                                    3[***]
*a.e. = acid equivalents; N/A = not applicable; G = ground; A = aerial; SD = dip or soil drench; ST = seed treatment; AB = airblast; B = brush, sponge or paint roller (to individual trees); T = treat rambutan panicles spraying a solution to runoff.
**Apples and pears are already approved uses.
***Shallowest depth of planting potatoes was obtained from the following source, accessed 08/27/2012: http://www.cals.uidaho.edu/potatoes/Research&Extension/Topic/Seed&Planting/EffectsOfRemovingSeedPieces&PlantingDepthOnPotatoYield-99.pdf (William H. Bohl and Stephen L. Love. 1999. Affects of Removing Seed Pieces and Planting Depth on Potato Yield).  Furthermore, the following site states that, "Generally the center of the seed piece should be planted 2 to 4 inches below field level and covered with 2 to 3 inches of soil." (Refer to http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/ae1040w.htm, the site was accessed 08/27/2012.)
##Even though the label is not clear on what is the application rate per acre, it appears to 0.11 lb a.e./A, similar to other crops.


