UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

SEP 2 .. a 2014 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: BEAD Chemical Profile (BCP) for Registration Review: Napthalene Acetates 

(NAA) (Case Number 0371) (1-Naphthaleneacetamide (056001), 1-

Naphthaleneacetic acid (056002), Potassium 1-naphthaleneacetate (056003), 

Ammonium 1-naphthaleneacetate (056004), Sodium 1-naphthaleneacetate 

(056007), and Ethyl 1-naphthaleneacetate (056008)). 

FROM: 

THRU: 

Carl Chen, Biologist 

Biological Analysis Branch 

Claire Paisley-Jones, Environmental Protection Specialist }_. _ 

Science Information and Analysis Branch (__ ~"-, _U' 

Michelle Ranville, Economist { tnf rr-Y) 

Biological 

Economic Analysis 

and Economic 

Branch 

Analysis 

U 

Division 

~ 

(7503P) 

Arnet Jones, Chief 

Biological Analysis Branc 

Diann Sims, Chief 

Science Information and Analysis Branch 

Timothy 

Economic 

Kiely, 

Analysis 

Chief 

Branch'\J 

r::\-J ~ Biological and Economic Analysis Divi~· 7503P) 

TO: Christina Scheltema, Chemical Review Manager 

Risk Management and Implementation Branch 1 

Pesticide Re-evaluation Division (7508P) 

Peer Review Panel date: August 3, 2014 

1 
SUMMARY 

NAA is a plant growth regulator registered for use in fruit crops such as apples and pears, olives, 

citrus, and avocados. It is also registered for use in nursery crops to control flower initiation. It 

is mainly used as a thinning agent to increase fruit size and quality and reduce fruit drop losses. 

Between 1998 and 2012, NAA was applied annually over approximately 200,000 acres of 

agricultural crops. The majority of usage is on apples and pears, and occurs on the west coast of 

the United States. Approximately five percent of olive acreage was treated with less than 500 

pounds ofNAA between 2004 and 2012. 

INTRODUCTION 

The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) provides an 

overview of the pest management roles and quantitative usage information for Napthalene 

Acetates (NAA) (Registration Review case number 0371). The BCP includes summaries of 

previous BEAD products and available public and/or private use and usage data for NAA to 

describe the role of this chemical in pest management. Additional information on uses is 

available in the NAA Label Data Report. Information provided in this BCP may be used by 

stakeholders (e.g., users and registrants), OPP risk and benefit assessors and OPP risk managers, 

and the general public during the Registration Review process of this pesticide. 

CHEMICAL AND USE CHARACTERISTICS 

NAA is a synthetic plant growth hormone registered for use in fruit crops such as apples, pears, 

olives, avocados, and citrus. It is also registered for ornamental uses. It contains an auxin that 

mimics the natural plant growth regulator, !-indoleacetic acid. NAA is mainly used for thinning 

of fruit to increase pome fruit size and quality and reducing pre-harvest fruit drop and losses 

from wind and mechanical knockdown (USDA, 1999a/2001). For citrus crops, it may be used as 

a fruit thinning agent or a separate concentrated formulation may be used to control sprouting 

(CCQC, 2003). For ornamentals, it delays leaf drop of holly boughs or acts as a rooting hormone 

labeled for use in greenhouses and nurseries (USDA, 2004). 

HISTORY OF NAA and BEAD PRODUCTS 

The NAA case includes six Als: 1-Naphthaleneacetamide (056001), 1-Naphthaleneacetic acid 

(056002), Potassium 1-naphthaleneacetate (056003), Ammonium 1-naphthaleneacetate 

(056004), Sodium 1-naphthaleneacetate (056007), and Ethyll-naphthaleneacetate (056008), all 

of which are plant growth regulators (PGRs). The first ofthese Ais, naphthaleneacetamide, was 

registered in 1952 to stimulate root growth of cuttings for a number of ornamentals and trees. In 

1981, tolerances were established for apples, pears, quinces, olives, and pineapple. A 

Registration Standard was published in 1981, and a Registration Eligibility Decision was 

published in 2007. Currently, NAA products are registered on fruit trees to prevent preharvest 

2 
fruit drop, delay flower induction, and thin foliage. NAA products are registered on ornamentals 

to stimulate growth and delay leaf drop. 

To date, no Section 18 emergency exemption requests have been submitted to the EPA for this 

chemical. However, this should not be interpreted as a lack of associated benefits. 

USE SITES, FORMULATIONS, AND APPLICATION METHODS 

The use sites and formulations ofNAA are summarized in Table 1. NAA can be applied by 

ground or air in sufficient water to ensure thorough coverage. NAA can also be applied as a 

foliar dip-only treatment for plant cuttings. 

T a e bl 1 . U se sites an dF ormua I ti ODS 0 fNAAA C f IVe I ogre d" 1ents 

NAAActive NonIngredient Formulations Agricultural Use Sites agricultural 

Use Sites 

Naphthaleneacetamide Flowable concentrate, Apples, pears -- (056001) Wettable powder 

Flowable concentrate, Apples, pears, gooseberries; non-bearing 

Naphthaleneacetic Ready-to-use solution, citrus, non-bearing nuts, non-bearing pome Ornamentals acid (056002) Soluble concentrate fruit, non-bearing stonefruit, non-bearing · 

berry plantings, non-bearing grapes 

Potassium 1- Apples, pears, olives, citrus, potato seed naphthaleneacetate Soluble concentrate -- (056003) treatment, holly (cut plant material) 

Ammonium 1-

naphthaleneacetate Soluble concentrate Apples, pears, olives, ornamental fruit trees -- _(056004} 

Sodium 1-

naphthaleneacetate Soluble concentrate Apples, pears, quince, loquat -- (056007) 

Ethyl1- Emulsifiable Apples, pears; non-bearing citrus, nonnaphthaleneacetate concentrate, Ready-to- bearing olives, non-bearing pome fruit, non- -- (056008) use solution, bearing avocado, non-bearing mango, 

multiple tree species 

USAGE 

BEAD currently has national usage data on five of the NAA products: the Naphthaleneacetates 

[Potassium 1-naphthaleneacetate (056003), Ammonium 1-naphthaleneacetate (056004), Sodium 

1-naphthaleneacetate (056007), and Ethyl1-naphthaleneacetate (056008)] and 

Naphthaleneacetamide (056001). The usage patterns of these two groups are discussed below. 

No usage data were available for Naphthaleneacetic acid (056002). 

N aphthaleneacetates 

Between 1998 and 2012, BEAD estimates that an average of approximately 7,000 lbs of 

Naphthaleneacetates [Potassium 1-naphthaleneacetate (056003), Ammonium 1-

3 
naphthaleneacetate (056004), Sodium 1-naphthaleneacetate (056007), and Ethyl 1-

naphthaleneacetate (056008)] were applied annually over approximately 180,000 acres (Figure 

1 ). While both the total acres treated and total pounds applied have fluctuated somewhat from 

year to year, and increased slightly in the last three years, overall average usage has remained 

quite consistent. 

300,000 

Total Acres 

Treated 

0 

I 

~ ~ 8 8 ~ ~ ~ ~ ~ b ~ ~ S ~ ~ m m o o o o o o o o o o o o o ~ ~ N N N N N N N N N N N N N 

- Total Acres Treated - Pounds AI 

12,000 

Total Pounds 

AI Applied 

0 

Figure 1. Naphthaleneacetates Total Acres Treated and Total Pounds AI Applied (1998-

2012). 

Source: Proprietary Data, 1998-2012 

Between 2008 and 2012,, the period following the RED, applications to apples accounted for 

approximately 70% of total pounds ofNaphthaleneacetates applied (4,600 lbs AI) and 

approximately 80% of average total acres treated (140,000 acres). Applications to pears 

accounted for the remaining 30% of pounds applied (2,000 lbs AI) and 20% of annual acres 

treated (35,000 acres) with Naphthaleneacetates. While apples account for the vast majority of 

usage, the average application rate on pear trees is nearly twice that of the average rate used on 

apples (Table 2). 

T a e bl 2 N . ap1 hth a I eneace t t a es u se b »Y c rop: A verage AI Rat e, 2008 -2012 

Crop Average Pounds Average Total Acres Avg.AIRate 

Treated* _{!_bs AI/ acres) 

Apples 4,600 140,000 0.033 

Pears 2,000 35,000 0.055 

*Total Acres Treated sums all acres treated for a crop, mcludmg those acres that receive multiple treatments. 

Source: EPA Proprietary Data, 2008-2012 

As shoWI) in Table 3, usage by state shows little variation over two time periods, immediately 

before and after the RED, both in terms of average annual pounds applied and states with highest 

4 
percent of usage. Usage in Washington accounted for over half of total pounds AI applied in 

both time periods, and usage in California accounts for another quarter of total usage. The 

remaining 15 states where usage was observed accounted for less than 10% oftotal pounds 

applied (Table 3). 

Table 3. Comparison of State Usage of Naphthaleneacetates, 

P t f T t I P d ercen o oa oun s AI A lpp1 li e d B e tw een th e 2003 -2007 an d 2008 -2012 . 2003-2007 2008-2012 

Average Annual = 6,800 lbs Average Annual =;: 6,600 lbs ,. 

State %Lbs State %Lbs 

Washington 55 Washington 62 

California 18 California 16 

Oregon 7 Oregon 8 

New York 6 Michigan 4 

Michigan 5 New York 3 

Other* 10 Other* 7 

*Other states: VA, PA, WV, NC, MO, ID, *Other states: VA, PA, WV, NC, OH 

IN, IL, OH, MA, WI, ME 

Source: Proprtetary Data, 2003-2012 

Figure 2 shows that usage intensity of naphthaleneacetates, in terms of pounds AI applied per 

1000 crop acres grown, is highest in the northwest, where the majority of apples and pears are 

grown in the U.S. 

Pounds Active Ingredient 

per 1,000 Crop Acres Grown 

CJ No Data 

0<0.02 

C]o.02-oos 

0.05-0.2 

->0.2 

Figure 2. Annual average agricultural use intensity ofNaphthaleneacetates (2008-2012). 

5 
Naphthylacetamide 

Between 1998 and 2012 an average of approximately 1,050 lbs ofNaphthylacetamide (056001) 

were applied annually over approximately 19,000 acres (Figure 2). Usage has fluctuated greatly 

during this period. Both total acres treated and total pounds applied decreased drastically 

between 2006 and 2007. Usage remained low until2012, when both total acres treated and total 

pounds applied quickly increased to a higher rate than the previous 2006 high. Because we do 

not have usage data for years after 2012, it is unclear whether this usage spike is an outlier or 

representative of an increasing trend. 

60,000 

Total Acres 

Treated 

0 I I I I 00 0'1 8 .-i N rtl '<t 

~ ~ 8 8 8 8 .-i .-i N N N N N 

Lfl 10 0 0 0 0 N N I' 00 0'1 0 .-i N 0 0 0 .-i .-i .-i 0 0 0 0 0 0 N N N N N N 

- Total Acres Treated - Pounds AI 

2,500 

0 

Total Pounds 

AI Applied 

Figure 3. Naphthylacetamide Total Acres Treated and Total Pounds AI Applied 

(1998-2012). 

Source: Proprietary Data, 1998-2012 

While Naphthylacetamide is registered for both apples and pears, 100% of reported agricultural 

usage is on apples. Usage ofNaphthylacetamide is much lower than usage of the 

Naphthalenacetates on apples (Table 4). Annually, nearly 80% fewer pounds of 

Naphthylacetamide (800 lbs AI) are applied to approximately 85% fewer acres of apples (18,000 

acres) than the Naphthalenacetates. However, the average AI rate is slightly higher. 

T a e bl 4 N . a pi hth 1y1ace I t . d am1e U se b C ~y ro >: A verage AI Rat e, 2008 -2012 ' Avg. AI Rate"' Crop Average Pounds Average Total Acres Treated* ,{lbs Al/acres) 

Apples 800 18,000 0.044 

*Total Acres Treated sums all acres treated for a crop, mcludmg those acres that receive multiple treatments. 

Source: EPA Proprietary Data, 2008-2012 

6 
Usage ofNaphthylacetamide is concentrated on the west coast, with the majority of usage 

occurring in Washington. Between 2003 and 2007, approximately 20% of total usage was seen 

in three eastern states: Virginia, West Virginia, and Pennsylvania. By 2008, however, only 1% of 

total observed usage occurred in the east, with less than 1% of total usage occurring in 

Pennsylvania (Table 5). 

Table 5. Comparison of State Usage of Naphthylacetamide, Percent of Total Pounds 

AI A ~PPJie r d B e tw een th e 2003 -2007 an d 2008 -2012 . 2003-2007 2008-2012 

Average Annual= 1,150 lbs Average Annual = 800 lbs 

State %Lbs State '"" %Lbs 

Washington 67 Washington 85 

Virginia 18 California 9 

California 11 Oregon 5 

West Virginia 4 Pennsylvania <1 

Other* <1 

*Other states: PA, OR 

Source: Proprietary Data, 2003-2012 

Figure 4 shows that usage intensity of naphthylacetamide, in terms of pounds AI applied per 

1000 crop acres grown, is highest in the northwest, where the majority of apples and pears in the 

U.S. are grown. More information about these maps is presented in Appendix A. 

Pounds Active Ingredient 

per 1,000 Crop Acres Grown 

c::::JNoDala 

C]<o.oo1 

D o.oo1- o.o1 

0.01 -0.02 

->0.02 

Figure 4. Annual average agricultural use intensity ofNaphthylacetamide (2008-2012). 

7 
Non-agricultural usage ofNAA 

Non-agricultural usage data were not available at the national level. However, California usage 

data indicated that the highest non-agricultural use ofNAA was for landscape maintenance 

(CDPR, 2003-2012). Usage for landscape maintenance has been slowly declining; 

approximately 100 lbs AI (primarily NAA, ammonium salt) were applied in 2012. 

ROLE OF NAA IN PEST MANAGEMENT AND CROP PRODUCTION 

NAA plays a significant role as a plant growth regulator in the apple and pear production. 

Approximately 60% of the pear acreage was treated with NAA recently, compared to less than 

10% treated with all other plant growth regulators (Proprietary Data, 2011-2012). It was also the 

top plant growth regulator used on apples (Proprietary Data, 2011-2012); it is applied, usually by 

aircraft, to aid in the retention of fruit on the tree during the final two to four weeks prior to 

harvest (USDA, 2001). NAA is recommended for use on apples in Washington and California 

(USDA, 2001; UC, 2006), which ranked first and second, respectively, among states in term of 

pounds AI applied in the last ten years (Proprietary Data, 2003-2012). 

Approximately 99% of the olives grown in the U.S. are grown in California. NAA is 

recommended for use on olive trees, which is an effective fruit thinner when applied 7-14 days 

following full bloom (USDA, 1999b). It was used to treat approximately five percent of the 

olive acreage in 1995 (USDA, 1999b ). Similarly, approximately five percent of olive acreage 

was treated with less than 500 pounds ofNAA between 2004 and 2012 (EPA, 2014). In 2012, 

approximately 1,400 acres of olives in California were treated with NAA (CDPR, 2012). 

DATA NEEDS 

. The Agency currently does not have certain important information on NAA. Obtaining the 

following information may improve future assessments conducted by the Agency related to the 

use and importance ofNAA. 

BEAD currently has no data on agricultural uses for 1-Naphthaleneacetic acid (056002) and no 

national-level data on non-agricultural usage. Data on lbs applied, target pests, application rates, 

and percent crop treated could inform future analyses by BEAD. 

8 
REFERENCES 

CCQC. 2003. Crop Profile- Citrus in California. California Citrus Quality Council (CCQC). 

Available at http:/ /downloadily.net/read/ccqc-crop-profile-120503-3-california-citrusquality-council-4 771 0934 .html 

CDPR. 2012. Summary of pesticide use data- Indexed by Chemicals. California Department of 

Pesticide Registration (CDPR). Available at 

http://www.cdpr .ca. gov/ docs/pur/pur 12rep/12sum.htm 

EPA. 2007. Registration Eligibility Decision Naphthaleneacetic Acid, its Salts, Ester, and 

Acetamide. Prevention Pesticides and Toxic Substances, US Environmental 

Protection Agency. 

EPA. 2014. Screening Level Estimates of Agricultural Use ofNAA (Case 0371). Office 

of Pesticide Programs, Biological and Economic Analysis Division. 

Proprietary Data. 1998-2012. (pesticide usage data) 

UC. 2006. UC Pest Management Guidelines- Apple thinning sprays. UC IPM Online. 

University of California Statewide Integrated Pest Management (IPM) Program. Available at 

http://www.ipm.ucdavis.edu/PMG/r4900 111.html. 

USDA. 1999a. Crop Profile for Pears in Oregon. 1999. The National Information System of the 

Regional Integrated Pest Management (IPM) Centers. United States Department of 

Agriculture (USDA). Available at http://www.ipmcenters.org/cropprofiles/docs/orpears.pdf. 

USDA. 1999b. Crop Profile for Olives in California. The National Information System of the 

Regional Integrated Pest Management (IPM) Centers. United States Department of 

Agriculture (USDA). Available at http://www.ipmcenters.org/cropprofiles/docs/Caolives.pdf. 

USDA. 2001. Crop Profile for Apples in Was~ngton. The National Information System ofthe 

Regional Integrated Pest Management (IPM) Centers. United States Department of 

Agriculture (USDA). Available at 

http://www.ipmcenters.org/cropprofiles/docs/W AApples.pdf. 

USDA. 2004. Crop Profile for Ornamental Plants in North Carolina. The National Information 

System of the Regional Integrated Pest Management (IPM) Centers. United States 

Department of Agriculture (USDA). Available at 

http:/ /www.ipmcenters.org/cropprofiles/ docs/N Cornamentals. pdf. 

9 
APPENDIX A 

The map included herein is primarily for the use of the risk assessors in the Environmental Fate 

and Effects Division. The map provides a very broad geographical view of the average annual 

amount (in pounds) of the active ingredient applied per 1 ,000 acres of crop acres grown. These 

data are included in the maps because risk assessors are interested in the amount of a pesticide 

used across agricultural land. The calculated values presented in the map are not equivalent to 

an application rate (lb a.i/A). 

The data used to make these maps have several limitations. Any interpretation of the maps 

should consider the underlying data and the associated limitations carefully. 

The numerator (annual average pounds applied) is based on private market surveys of pesticide 

use in agriculture averaged over the last five years (Proprietary Data, 2008-2012). These surveys 

cover about 60 crops and are targeted in states that produce the majority of the crop. Although 

the surveys capture most of the use of a particular active ingredient in agriculture, there are 

several limitations to these surveys. 

• States with minor production of a surveyed crop are not sampled 

• Not all types of pesticides are surveyed in every crop in every year 

• Many specialty crops with very small acreages are not included in the survey 

The result of these limitations is that states that show no usage may actually have a small amount 

of the active ingredient being used. In some cases the displayed use intensity may be distorted 

because the surveyed crops and the reported pesticide usage may not accurately represent the 

actual pesticide usage on the crops produced in the state. 

The denominator (1,000 crop acres grown) was also obtained from the same private market 

survey database. The "Crop Acres Grown" variable represents the total acres grown in a given 

state of all of the surveyed crops. This value is independent of pesticide usage and pesticide 

registration. It is important to note that the surveyed crops (about 60) are sampled from states 

that are major producers of each crop. Therefore, there are cases where the actual crop acreage in 

a state is higher than that reported by crop acres grown in the survey because either that state 

and/or crop was not included in the survey. 

The reader should pay particular attention to the figure legends and realize that a map prepared 

for a particular chemical is not directly comparable to a map prepared for a different chemical as 

the legend bins will likely be different. 

10