NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

MEMORANDUM

Date: October 3, 2012

SUBJECT: 1-Naphthaleneacetic acid (NAA), its salts, ester, and acetamide . Expansions of 

Existing Crop Group/Representative Commodity Uses to Fruit, Pome, Group 11-

10 and New Uses in/on Avocado, Mango, Mamey Sapote, and Rambuttan. 

Summary of Analytical Chemistry and Residue Data. 

PC Code: 056002 DP Barcode: 399621

Decision No.: 461439 Registration Nos.: 5481-429 and 5481-541

Petition No.: 2E7991 Regulatory Action: Amended Section 3

Risk Assessment Type: NA Case No.: 0379

TXR No.: NA CAS No.: 86-87-3

MRID Nos.: 48749901 and 02 40 CFR: 180.155

 

FROM: Gary Otakie, Chemist

Risk Assessment Branch 4

Health Effects Division (7509P)

THROUGH: Susan V. Hummel, Senior Scientist

Elissa Reaves, PhD., Branch Chief

Risk Assessment Branch 4

Health Effects Division (7509P)

TO: Thurston Morton, Risk Assessor

Risk Assessment Branch 4

Health Effects Division (7509P)

And

Laura Nollen/Barbara Madden

Risk Integration, Minor Use & Emergency Response Branch

Registration Division (7505P)
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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Action Requested

Under PP#2E7991, The Interregional Research Project Number 4 (IR-4) has submitted a petition 

for the establishment of permanent tolerances for residues of the plant growth regulator 1-

Naphthaleneacetic acid (NAA) in conjunction with requests for amended Section 3 registrations 

of the two pesticide formulations: TRE-HOLD Sprout Inhibitor A112, and Fruitone N. The 

petitioner is proposing the establishment of the following permanent tolerances for residues of 

NAA:

Avocado...................................................................................0.05 ppm

Mango .......................................................................................0.05 ppm

Mamey Sapote ........................................... 0.05 ppm

Rambuttan ................ ........................................... 3.0 ppm

Fruit, pome, group 11- 10 ......................................................0.15 ppm

Discussion

1-Naphthaleneacetic acid (NAA), its salts, ester, and acetamide are plant growth regulators 

(PGR) which are collectively referred to as naphthalene acetates. The PGR activity of NAA is 

due to its structural similarity to the natural plant hormone indole acetic acid (IAA). They are 

currently registered for use on various orchard and fruit crops to prevent preharvest drop of fruits, 

thin fruit trees, and delay flower induction. They can also stimulate growth and delay leaf drop on

ornamentals.

New residue chemistry data on avocado and rambuttan were submitted to support these uses, 

except for the Fruit, pome, group 11-10, which is an expansion of the current crop group 

tolerance on “Fruit, pome, group 10”, and relies on existing residue data.

Residues of NAA were below the LOQ (<0.05 ppm) in/on avocado harvested 9-11 days 

following either one or two paintbrush or sponge applications of a 1.27-1.30% ai solution of the 

15.1% EC formulation of NAA ethyl ester. 

Following one foliar directed application of the 3.5% SC formulation of NAA sodium salt at 90 

and 900 ppm (i.e. 1X and 10X), respectively, residues (and per trial averages) of NAA in/on 

rambutan fruit harvested at a 2-day PHI were 0.0786-0.636 (0.108-0.621) and 1.25-5.06 (1.35-

4.95) ppm. 

There are an adequate number of avocado and rambuttan field trials with acceptable field trial 

data from representative geographical locations. 

A tolerance level of 0.15 ppm, for Fruit, pome, group 11-10 is appropriate to cover the use of 

NAA on the Fruit group 11. The Organisation for Economic and Co-operation Development 

(OECD) Tolerance Estimation Procedures were used to determine appropriate tolerance levels 

for Rambuttan, while for avocado the tolerance is based of the level of quantitation (0.05 ppm). 
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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A tolerance of 2.0 ppm rather than 3.0 ppm is required for rambuttan. Note that this tolerance 

level is different than that proposed by the petitioner who used NAFTA tolerance 

estimation procedures. 

Tolerances are established under 40CFR§180.155(a) for the combined residues of 1-

naphthaleneacetic acid and its conjugates calculated as 1-naphthaleneacetic acid from the 

application of 1-naphthaleneacetic acid, its ammonium, sodium, or potassium salts, ethyl ester, 

and acetamide in/on sweet cherry, fruit pome group 11, olive, orange, pineapple, and tangerine. 

A time-limited tolerance under 40CFR§180.155(b) is also established for avocado (expires 

12/31/12) in connection with a Section 18 emergency exemption. The established tolerances 

range from 0.05 ppm to 0.15 ppm.

The current tolerance expression for NAA is not in accord with our current guidance. See 

Conclusion below for appropriate wording.

Conclusion

1

In brief, a revised Section F proposing a tolerance of 2.0 ppm for NAA in/on Rambuttan is 

required.

HED has examined the residue chemistry database for NAA.. With regards to NAA for 

PP#2E7991, pending submission and revised Sections B and F (see requirements under 

Recommended Label Changes and Tolerance Recommendations), there are no residue chemistry

issues that would preclude granting amended registrations for amended Section 3 registrations of 

six pesticide formulations: containing NAA for use on a variety of crops, and to expand 

currently registered foliar uses or establishment of tolerances for residues of NAA only in/on the 

following commodities:

Avocado...................................................................................0.05 ppm

Mango .......................................................................................0.05 ppm

Mamey Sapote ........................................... 0.05 ppm

Rambuttan ................ ........................................... 2.0 ppm

Fruit, pome, group 11-10 .......................................................0.15 ppm

The amended registrations are limited to expansions to add the commodities specified under the 

new crop groups/subgroups and Avocado, Mango, Mamey Sapote, Rambuttan and do not include 

substantive changes to currently registered use patterns (i.e., maximum use rates, retreatment 

intervals, preharvest intervals, use of adjuvants, etc.). 

Tolerance Recommendations

A revised Section F is needed, proposing tolerances as follows:
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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Avocado...................................................................................0.05 ppm

Mango .......................................................................................0.05 ppm

Mamey Sapote ........................................... 0.05 ppm

Rambuttan ................ ........................................... 2.0 ppm

Fruit, pome, group 11-10 .......................................................0.15 ppm

The current tolerance expression for NAA is not in accord with our current guidance. The 

tolerance expression should read:

Tolerances are established for the combined residues of 1-naphthaleneacetic acid, including 

its metabolites and degradates in/on avocado at 0.05 ppm, mango at 0.05 ppm, Mamey 

Sapote at 0.05 ppm, Rambuttan at 2.0 ppm, and Fruit, pome, group 11 at 0.15 ppm. 

Compliance with the tolerance levels specified is to be determined by measuring only 1-

naphthaleneacetic acid and its conjugates, calculated as the Stoichiometric equivalent of 1-

naphthaleneacetic acid, in or on the commodity.

Recommended Label Changes. The Fruitone L label must have a pounds per gallon statement. 

Aerial application must be made in a minimum of 10 gallons/acre.

A human health risk assessment is forthcoming.

Note to PM:

* Use information was taken from Section B of the petition. Only use information for the 

proposed new uses on Avocado, Mango, Mamey Sapote and Rambuttan were reviewed. HED 

has not checked the labels to ensure that use directions for currently registered uses have not 

been revised. The PM must ensure that the use directions for the remaining commodities have 

not changed since any changes required in the RED were made.

Tolerances should be revised, as needed, to reflect the correct commodity definitions as specified 

in Table 10. 

A human heath risk assessment is forthcoming.
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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Background

The chemical structure and nomenclature of -Naphthaleneacetic acid (NAA), its salts, ester, and 

acetamide and the physicochemical properties are presented in Tables 1 and 2. 

Table 1. NAA Nomenclature

Chemical structure O

NH2

O

OH

Common name NAA acetamide NAA

Molecular Formula C12H11NO C12H10O2

Molecular Weight 185.23 186.20

IUPAC name 2-(1-naphthyl)acetamide 2-(1-naphthyl)acetic acid

CAS name 1-naphthaleneacetamide 1-naphthaleneacetic acid

CAS # 86-86-2 86-87-3

PC Code 056001 056002

Chemical structure O

O K

+

O

O NH4

+

Common name NAA potassium salt NAA ammonium salt

Molecular Formula C12H10O2K C12H13NO2

Molecular Weight 224.31 203.24

IUPAC name potassium-2(1naphthyl)acetate ammonium-2(1naphthyl)acetate

CAS name 1-naphthalnene acetic acid, potassium salt 1-naphthaleneacetic acid, ammonium salt

CAS # 15165-79-4 25545-89-5

PC Code 056003 056004
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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Table 1. NAA Nomenclature

Chemical structure O

O Na

+

O

O CH3

Common name NAA sodium salt NAA ethyl ester

Molecular Formula C12H10O2Na C14H14O2

Molecular Weight 208.2 214.26

IUPAC name sodium-2(1naphthyl)acetate ethyl-2(1naphthyl)acetate

CAS name 1-Naphthaleneacetic acid, sodium salt 1-Naphthaleneacetic acid, ethyl ester

CAS # 61-31-4 2122-70-5

PC Code 056007 056008

Table 2. Physicochemical Properties of NAA1

Parameter Value Reference

Active Ingredient NAA acetamide

Melting point/range 182-184 C Farm Chemicals Handbook

pH of 1% aqueous suspension 5.1 Product CSF

Density or specific gravity 0.221 g/cm3Product CSF

Water solubility (20 C) not available

Solvent solubility (20 C) not available

Vapor pressure at 20 C not available

Dissociation constant (pKa) not available

Octanol/water partition coefficient (Kow) not available

UV/vis absorption spectrum not available

Active ingredient NAA

Melting point/range 130 C Farm Chemicals Handbook

pH of 1% aqueous suspension 3.45 RD D265117, 5/15/00, B. Kitchens

Density or specific gravity 0.45 g/mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Water solubility (20 C) 0.042 g/100 mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Solvent solubility (20 C) xylene 5.5 g/100 mL

CCl4 1.06 g/100 mL

freely soluble in acetone, ether, 

and chloroform

CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Farm Chemicals Handbook

Vapor pressure at 20 C 0.3 mm Hg at 26 C CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Dissociation constant (pKa) 3.16 x 10-4 CB Nos. 3970 and 3971, 7/5/88, F. Suhre

Octanol/water partition coefficient (Kow) not applicable; polar compound

UV/vis absorption spectrum not available

Active ingredient NAA sodium salt

Melting point/range >300 C CB Nos. 3468 and 3469, 6/3/88, F. Suhre
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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Table 2. Physicochemical Properties of NAA1

Parameter Value Reference

pH of 1% aqueous suspension 9.1 CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Density or specific gravity 0.46 g/mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Water solubility (20 C) 340 g/100 mL CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Solvent solubility (20 C) insoluble in nonpolar solvents CB Nos. 3468 and 3469, 6/3/88, F. Suhre

Vapor pressure at 20 C not available

Dissociation constant (pKa) 3.16 x 10-4 CB Nos. 3970 and 3971, 7/5/88, F. Suhre

Octanol/water partition coefficient (Kow) not applicable; polar compound

UV/vis absorption spectrum not available

Active ingredient NAA ethyl ester

Boiling point/range >150 C Old unreviewed Union Carbide data

pH of 1% aqueous suspension not available

Density or specific gravity 1.11 at 20 C Old unreviewed Union Carbide data

Water solubility (20 C) insoluble Old unreviewed Union Carbide data

Solvent solubility (20 C) soluble in xylene, toluene, 

ethanol, acetone, and methyl 

ethyl ketone

Old unreviewed Union Carbide data

Vapor pressure at 20 C not available

Dissociation constant (pKa) not available

Octanol/water partition coefficient (Kow) not available

UV/vis absorption spectrum not available

1 No physicochemical properties information was available concerning the NAA potassium and ammonium salts.
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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860.1200 Directions for Use

The petitioner has submitted copies of the proposed labels for Tre-Hold Sprout Inhibitor A-112 

and Fruitone L. Tre-Hold Sprout Inhibitor A-112 is a soluble concentrate formulation 

containing 15.1% NAA, ethyl ester (1 lb/gal NAA). Fruitone L is a soluble concentrate 

formulation containing 3.5% NAA, sodium salt. The pounds per gallon statement is missing. The 

proposed use directions are presented in Table 3 below. 

Table 3. Summary of Directions for Use of NAA, potassium and sodium salts

Applic. Timing, 

Type, and 

Equip.

Formulation Applic. Rate 

(lb ae/A)

Max. No. 

Applic. per 

Season

Max. 

Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Avocado, Mango, and Mamey Sapote

Foliar spray/

brush/sponge/ 

paint roller

TRE-Hold Sprout Inhibitor A112, EPA Reg. No. 5481-429;

15.1 % NAA, ethyl ester (1 

lb/ gal)

0.078 lb ae/gal

11 oz. 

product/gallon

(1.1% w/w)

two per 

year

10 days

Use Directions and Limitations: Prune and treat pruned branches and limbs within a few days. 

Apply an average of 3 fluid ounces mixture per tree. A minimum 45-day RTI is specified. The 

REI is 12 hours.

Rambutan 

Foliar spray

Fruitone L, EPA Reg No. 

5481-541 (3.1 % NAA)

90 ppm solution one per year 2 days

Use Directions and Limitations: Spray Rambuttan panicles to runoff. The REI is 12 hours.

Fruit, Pome, Group 11-10

For chemical 

thinning: Foliar 

spray, Aerial

Fruitone L, EPA Reg No. 

5481-541 (3.1 % NAA)

0.5 to 4.0 fl 

oz/100 gal NS NS Fruit set

Use Directions and Limitations: Apply at petal fall and/or early fruit set. Ensure uniform spray 

coverage using tree row volume. For ground applications use up to 500 gal water per acre. For 

aerial applications, use 5-10 gallons of water per acre. Directions provided for apples and pears. 

For other fruits in crop group, follow directions for thinning.

To control preharvest drop: 

Foliar spray, 

Aerial

Fruitone L, EPA Reg No. 

5481-541 (3.1 % NAA) 0.11 NS 150 g/A 2 days

Use Directions and Limitations: Use sufficient water to ensure coverage, by air a minimum of 5 

gallons. A typical application is 8-32 fl oz per acre, made 1-4 weeks prior to harvest. If needed, 

repeat at weekly intervals. Directions provided for apples and pears.

Conclusion. The proposed use directions are adequate to allow evaluation of the residue data 

relative to the proposed uses. The Fruitone L label must have a pounds per gallon statement. 

Aerial application must be made in a minimum of 10 gallons/acre.
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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860.1300 Nature of the Residue – Plants

RED Residue Chemistry Chapter D299296, 10 MARCH 2004, G. Otakie

Acceptable apple and olive metabolism studies have been previously submitted and reviewed. 

Based on the nature of residues identified from the apple and olive metabolism studies, HED has 

previously determined that the terminal residues of concern in plants are the parent compounds, 

NAA and its conjugates and that the qualitative nature of the residues in plants (i.e., orchard 

trees) is adequately understood. For purposes of the current petition the nature of the residue in 

plants is adequately understood.

860.1300 Nature of the Residue - Livestock

RED Residue Chemistry Chapter D299296, 10 MARCH 2004, G. Otakie

An acceptable goat metabolism study has been previously submitted and reviewed. Based on 

these data, HED has previously concluded that the qualitative nature of the residue in ruminants 

is adequately understood. The terminal residues of concern in ruminants are the parent 

compounds, NAA and its conjugates. 

The available ruminant metabolism data are adequate to support the proposed uses. There are no 

poultry feed items associated with currently registered or proposed food uses of NAA; thus a 

poultry metabolism study is not required.

860.1340 Residue Analytical Methods

RED Residue Chemistry Chapter D299296, 10 MARCH 2004, G. Otakie

Enforcement and data collection methods: The residue analytical methods, currently listed in 

Volume II of the Pesticide Analytical Methods, are inadequate for the enforcement of tolerances 

for residues of a-naphthaleneacetic acid (Pesticide Reg. Sec. 180.155) and anaphthaleneacetamide (Pesticide Reg. Sec. 180.309) in/on plant commodities because these 

methods use benzene, a hazardous or toxic reagent.

An HPLC method using fluorescence detection (Method NAA-AM-001) for apples and peas and 

a similar method for olives and olive oil (Method NAA-AM-002) has been previously submitted 

for determination of NAA in plant commodities. These methods include extraction with water 

and incorporate a basic hydrolysis step to release bound residues. These methods do not use 

benzene or diazomethane which are being discouraged by the Agency for safety reasons. Theses 

methods have been subjected to successful independent laboratory validations. Acceptable 

recoveries were obtained from apples, olives and olive oil fortified with NAA at the method 

LOQ (0.01 ppm) and at 1.0 ppm. This method is suitable for enforcement.
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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Avocado samples were analyzed using an HPLC/UV method adapted from Morse Laboratories, 

Inc. Analytical Method NAA-AM-003 entitled “Recommended Analytical Residue Method for 

1-Naphthaleneacetic Acid, 1-Naphthaleneacetamide, and/or 1-Naphthaleneacetic Acid Ethyl 

Ester, in Grape (red and white), Grapefruit, Tomato, and Green Bell Pepper Matrices”. The 

method is a common moiety method that converts residues of NAA acetamide and NAA ethyl 

ester to NAA. A number of minor modifications to the method were specified including changes 

in clean-up procedures, reagents, and sample sizes. 

Rambutan samples were analyzed using an HPLC method adapted from Morse Laboratories, Inc. 

Analytical Method NAA-AM-003 entitled “Recommended Analytical Residue Method for 1-

Naphthaleneacetic Acid, 1 Naphthaleneacetamide, and/or 1-Naphthaleneacetic Acid Ethyl Ester, 

in Grape (red and white), Grapefruit, Tomato, and Green Bell Pepper Matrices”. The method is a 

common moiety method that converts residues of NAA acetamide and NAA ethyl ester to NAA. 

A number of minor modifications to the method were specified including changes in clean-up 

procedures, reagents, and sample sizes. 

860.1360 Multiresidue Methods

D232463, D294854, 30 OCT 2003, G. Otakie

Multiresidue method (MRM) data have been submitted previously in support of the registration 

of NAA, its salts, ester and acetamide. Naphthaleneacetamide was found to chromatograph 

satisfactorily using Pesticide Analytical Manual (PAM) Vol. I, Section 302 DG 5. 

Naphthaleneacetamide was found to produce a 50% full scale deflection (FSD) with a 50 

nanogram injection and the relative retention time to chlorpyrifos is approximately 0.8. Average 

recoveries for naphthaleneacetamide spiked into pears at approximately 0.1 ppm and 1.0 ppm 

were 97.8 and 104%, respectively, for Section 302, method E1, without Florisil cleanup. Apple 

spikes using this procedure could not be quantified due to interference in the apple matrix. 

Naphthaleneacetamide was found not to be recoverable through Florisil, so it would not be 

recoverable through Protocols E or F. Therefore, testing under PAM Vol. I Protocol E, for 

apples and pears, and Protocol F, for olives, was suspended prior to recovery experiments 

through the entire Sections 303 and 304 methods. FDA MRM’s are not suitable as enforcement 

methods for NAA.

860.1380 Storage Stability

RED Residue Chemistry Chapter D299296, 10 MARCH 2004, G. Otakie

Adequate storage stability data have been submitted and reviewed for apples, pears, and olives. 

These data indicate that residues of 1-naphthaleneacetic acid are reasonably stable under frozen 

storage conditions in/on the above commodities for up to 12 months. 

The current submission included storage stability data which showed NAA and NAA ethyl ester 

stored in frozen avocado were stable for up to 27 months and stored in frozen Rambuttan stable 

up to 25 months. The storage stabilty data adequately support the storage conditions and samples 

collected from the avocado and Rambuttan field trials.
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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860.1400 Water, Fish, and Irrigated Crops

There are no proposed uses that are relevant to this guideline topic.

860.1460 Food Handling

There are no proposed uses that are relevant to this guideline topic.

860.1480 Meat, Milk, Poultry, and Eggs

RED Residue Chemistry Chapter D299296, 10 MARCH 2004, G. Otakie

Livestock

There are no livestock feedstuffs associated with the current new proposed uses. At this time, the 

Agency has determined that NAA is in Category 6(a)(3) (i.e., no reasonable expectations of finite 

residues of concern in meat and milk). 

Poultry

There are no poultry feed items associated with the currently registered or proposed food/feed 

uses of naphthalene acetates; thus, a poultry feeding study is not required. Tolerances for the eggs 

and edible tissues of poultry need not be established.

860.1500 Crop Field Trials

48749901.der

Avocado

Residue data from the avocado crop field trials are reported in Table 1. A summary of the 

residue data is presented in Table 2. Residues of NAA were below the LOQ (<0.05 ppm) in/on 

avocado harvested 9-11 days following either one or two paintbrush or sponge applications of a 

1.27-1.30% ai solution of the 15.1% EC formulation of NAA ethyl ester. Applications made to 

cut surface and surrounding branches. Samples were harvested from each plot at a 2-day PHI.

In the residue decline trial, residues of NAA in/on avocado were below the LOQ at all PHIs; 

therefore, residue decline could not be assessed. 
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TABLE 6 Residue Data from Avocado Field Trials with NAA ethyl ester.

Trial ID (City, 

State; Year)1

Zone Avocado

Variety

Commodity Total Rate

(% solution)

PHI

(days)

NAA Residues2 [Average]

Homestead, FL; 

2006 (-FL41)

3 Lula Fruit 1 x 1.27% 10 <0.050, <0.050 [<0.050]

2 x 1.27% 11 <0.050, <0.050 [<0.050]

Exeter, CA; 2006 

(-CA95)

10 Zutano Fruit 1 x 1.27% 10 <0.050, <0.050 [<0.050]

2 x 1.27% 9 <0.050, <0.050 [<0.050]

Irvine, CA; 2006 

(-CA96, -CA97, 

and -CA98)

[Target PHI]

10 Hass Fruit 1 x 1.28-

1.30%

10-11 <0.050, <0.050, <0.050, <0.050, <0.050,

<0.050 [<0.050]

2 x 1.28-

1.30%

10 <0.050, <0.050, <0.050, <0.050, <0.050,

<0.050 [<0.050]

Irvine, CA; 2006 

(-CA96)

[Additional 

Decline PHIs]

10 Hass Fruit 1 x 1.30% 1 <0.050, <0.050 [<0.050]

7 <0.050, <0.050 [<0.050]

15 <0.050, <0.050 [<0.050]

21 <0.050, <0.050 [<0.050]

2 x 1.30% 1 <0.050, <0.050 [<0.050]

6 <0.050, <0.050 [<0.050]

14 <0.050, <0.050 [<0.050]

21 <0.050, <0.050 [<0.050]

1

 HED has concluded that trials -CA96/-CA97/-CA98 constitute a single trial with replicate samples for purposes of 860.1500 

data requirements.

2

 A total of two applications of solution were made at each trial site, with samples collected after each application.

3

 Residues of NAA ethyl ester were determined by a common moiety method that converts residues of NAA acetamide and NAA 

ethyl ester to NAA. The LOQ was 0.05 ppm. 

TABLE 7 Summary of Residue Data from Avocado Field Trials with NAA ethyl ester.

Commodity Analyte Total

Rate

(% solution)

PHI (days) Residue Levels (ppm)1

n Sample 

Min.

Sample 

Max.

LAFT2 HAFT2 Median Mean Std. 

Dev.

Avocado, 

Fruit

NAA32 x 1.28-1.30% 10-11 3 <0.05 <0.05 <0.05 <0.05 0.05 0.05 N/A

2 x 1.28-1.30% 9-11 3 <0.05 <0.05 <0.05 <0.05 0.05 0.05 N/A

1

 Except for sample min/max, values reflect per trial averages; n = no. of field trials. N/A = not applicable.

2

 LAFT = lowest average field trial; HAFT = highest average field trial.

3

 Residues of NAA ethyl ester were determined by a common moiety method that converts residues of NAA acetamide and NAA 

ethyl ester to NAA. 

An issue was raised about the separation distance for the avocado field trials. The petitioner indicated that 

since the study was conducted in 2006, the trial separation guidance developed for 2012 studies was not 

achievable because of the unique application method used in the study.
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Conclusions

The submitted avocado field trial data are adequate. Residues of NAA were below the LOQ 

(<0.05 ppm) in/on avocado harvested 9-11 days following either one or two paintbrush or sponge 

applications of a 1.27-1.30% ai solution of the 15.1% EC formulation of NAA ethyl ester. In the 

residue decline trial, residues of NAA in/on avocado were below the LOQ at all PHIs; therefore, 

residue decline could not be assessed. 

An acceptable method was used for residue quantitation, and adequate data were submitted to 

support sample storage intervals and conditions.

48749902.der

Rambuttan

Residue data from the rambutan field trials are reported in Table 3. A summary of the residue 

data are presented in Table 4. Following one foliar directed application of the 3.5% SC 

formulation of NAA sodium salt at 90 and 900 ppm, (i.e. 1X and 10X) sprayed to runoff 

respectively, residues (and per trial averages) of NAA in/on rambutan fruit harvested at a 2-day

PHI were 0.0786-0.636 (0.108-0.621) and 1.25-5.06 (1.35-4.95) ppm. 

Residue decline data were not submitted and are not needed for crops requiring three or fewer 

trials.

TABLE 8 Residue Data from Rambutan Field Trials with NAA sodium salt.

Trial ID (City, 

State; Year)

Zone Rambutan

Variety

Commodity Total Rate

(ppm)

PHI

(days)

NAA Residues1 [Average]

Kurtistown, HI; 

2007 (-HI08)

13 Jit Lee Fruit 90 2 0.0786, 0.137 [0.108]

900 2 1.25, 1.44 [1.35]

Pepeekeo, HI; 

2007 (-HI09)

13 Jit Lee Fruit 90 2 0.605, 0.636 [0.621]

900 2 4.83, 5.06 [4.95]

1

 Residues were determined by a common moiety method that converts residues of NAA acetamide and NAA ethyl ester to 

NAA. Per trial averages were calculated by the study reviewer.

TABLE 9 Summary of Residue Data from Rambutan Field Trials with NAA sodium salt.

Commodity Analyte Total Rate

(ppm)

PHI 

(days)

Residue Levels (ppm)1

n Sample 

Min.

Sample 

Max.

LAFT2 HAFT2 Median Mean Std. 

Dev.

Rambutan, Fruit NAA390 2 2 0.0786 0.636 0.108 0.621 0.365 0.365 0.363

900 2 2 1.25 5.06 1.35 4.95 3.15 3.15 2.55

1

 Except for sample min/max, values reflect per trial averages; n = no. of field trials. 

2

 LAFT = lowest average field trial; HAFT = highest average field trial.

3

 Residues were determined by a common moiety method that converts residues of NAA acetamide and NAA ethyl ester to 

NAA. Per trial averages were calculated by the study reviewer.
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

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Conclusions

The submitted rambutan field trial data are adequate. Following one foliar directed application 

of the 3.5% SC formulation of NAA sodium salt at 90 and 900 ppm, respectively, residues (and 

per trial averages) of NAA in/on rambutan fruit harvested at a 2-day PHI were 0.0786-0.636 

(0.108-0.621) and 1.25-5.06 (1.35-4.95) ppm. Residue decline data were not submitted.

An acceptable method was used for residue quantitation, and adequate data were submitted to 

support sample storage intervals and conditions.

Summary - Pome Fruit Group (Crop Group 11-10)

Representative crops for the pome fruit crop group are apples and pears.

D306440, 04/30/2009, G. Otakie

Per the referenced review this tolerance was revised to 0.15 ppm in 2009:

“New HED tolerance assessment procedures incorporating statistical procedures (i.e. NAFTA 

MRL Calculator) subsequent to the NAA Registration Standard indicate the 0.1 ppm tolerance 

for NAA in/on Pome Fruits should be raised to 0.15 ppm.”

860.1520 Processed Food and Feed

There are no processed commodities associated with the proposed uses in the current petition

860.1650 Submittal of Analytical Reference Standards

Analytical reference standards for NAA are available at the EPA National Pesticide Standards 

Repository. The tolerance expression includes only NAA, so this is sufficient.

860.1850/ 860.1900 Confined/Field Accumulation in Rotational Crops

There are no rotational crop data requirements associated with the proposed uses in the current 

petition. 

860.1550 Proposed Tolerances

Tolerances are established under 40CFR§180.155(a) for the combined residues of 1-

naphthaleneacetic acid and its conjugates calculated as 1-naphthaleneacetic acid from the 

application of 1-naphthaleneacetic acid, its ammonium, sodium, or potassium salts, ethyl ester, 

and acetamide in/on sweet cherry, fruit pome group 11, olive, orange, pineapple, and tangerine. 
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

Page 15 of 16

A time-limited Section 18 emergency exception tolerance under 40CFR§180.155(b) is also 

established for avocado (expires 12/31/12). The established tolerances range from 0.05 ppm to 

0.15 ppm. 

No Codex, Canadian, or Mexican maximum residue limits (MRLs) have been established for 

residues of (NAA), its salts, ester, and acetamide for the use in this petition..

Table 10 Tolerance Summary for NAA

Commodity Established/Proposed 

Tolerance (ppm)

Recommended 

Tolerance (ppm)

Comments; Correct Commodity 

Definition

Tolerances Proposed Under PP#2E7991

Avocado 0.05

Mango 0.05

Mamey Sapote 0.05

Rambuttan 3.0 2.0

Fruit, pome, group 11-

10

0.15

Tolerances That Need Amended Under PP#2E7991

Rambuttan Proposed 3.0 ppm 

(Section F)

2.0 ---

Attachments: 

Appendix I – Tolerance Assessment Calculations

F. DOCUMENT TRACKING

RDI: G. Otakie 10/03/12; S. Hummel 10/03/12

Petition Number: 2E7991

DP#: 399621

PC Code: 129032

Template Version September 2005
NAA Summary of Analytical Chemistry and Residue Data DP#: D399621

Page 16 of 16

Appendix I – Tolerance Assessment Calculations

NAA

Rambutan

US

90 ppm 2-day PHI

Total number of data (n) 4

Percentage of censored data 0%

Number of non-censored data 4

Lowest residue 0.079

Highest residue 0.636

Median residue 0.371

Mean 0.364

Standard deviation (SD) 0.297

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 0.636

- Mean + 4 SD 1.553

- CF x 3 Mean 1.092

Unrounded MRL 1.553

Rounded MRL 2

High uncertainty of MRL estimate.

[Small dataset]

Residues (mg/kg) n

0.0786 1

0.137 1

0.605 1

0.636 1