1

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), 
2

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®Sprout Inhibitor A-112, and Fruitone®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.

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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.

 

1 The abbreviation a.e. refers to acid equivalents (i.e., lbs of NAA, its salts and ester, expressed as lbs of NAA).
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Table 2. Summary use information for naphthalene acetates, based on the 2007 revision of the RED, 

the label for Rejuvenate Seed Treatment2, and the proposed labels for Tre-Hold®Sprout Inhibitor A1123

, and Fruitone® L

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. 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&PlantingDepthOnP

otatoYield-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.

 

2 Rejuvenate Seed Treatment (EPA Reg. No. 87320-2) contains 6.25% K-NAA or 0.44 lb NAA a.e./gallon.

3 Tre-Hold®

Sprout Inhibitor A-112 (EPA Reg. No. 5481-429) contains 15.1% EE-NAA or 1 lb Na-NAA 

a.e./gallon.

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Fruitone L®(EPA Reg. No. 5481-541) contains 3.5% Na-NAA or 3.1% NAA a.e.