# Naphthalene Acetic Acid, Its Salts, Ester and Acetamide R.E.D. FACTS

Chemical Review Manager: Mark T. Howard (<howard.markt@epa.gov>),
703-308-8172 ![](media/image1.png){width="8.333333333333333e-3in"
height="8.333333333333333e-3in"}

Publication number: **EPA 738-F-07-017**

#### Pesticide Reregistration

All pesticides sold or distributed in the United States must be
registered by EPA, based on scientific studies showing that they can be
used without posing unreasonable risks to people or the environment.
Because of advances in scientific knowledge, the law requires that
pesticides first registered before November 1, 1984, be reregistered to
ensure that they meet today\'s more stringent standards.

In evaluating pesticides for reregistration, EPA obtains and reviews a
complete set of studies from pesticide producers that describe the human
health and environmental effects of each pesticide. To implement
provisions of the Food Quality Protection Act (FQPA) of 1996, EPA
considers the special sensitivity of infants and children to pesticides,
as well as aggregate exposure of the public to pesticide residues from
all sources, and the cumulative effects of pesticides and other
compounds with common mechanisms of toxicity. The Agency develops any
mitigation measures or regulatory controls needed to effectively reduce
each pesticide\'s risks. EPA then reregisters pesticides that meet
current human health and safety standards and ensures they can be used
without posing unreasonable risks to human health and the environment.

When a pesticide is eligible for reregistration, EPA explains the basis
for its decision in a Reregistration Eligibility Decision (RED)
document. This fact sheet summarizes the information in the RED document
for the naphthalene acetate pesticides, Naphthalene Acetic Acid, Its
Salts, Ester, and Acetamide, reregistration case number 0379.

#### Regulatory History 

The first naphthalene acetate end-use product (with naphthalene
acetamide as the active ingredient), Rootone Brand Rooting Hormone with
Fungicide, was registered in 1952. Its labeled use was to stimulate root
growth of cuttings of a number of ornamental plants, vines and shrubs,
deciduous trees, and evergreens. Seven more naphthalene acetates,
including naphthalene acetic acid (NAA), were registered in the early to
mid-1960s. There are six active ingredients currently registered as part
of the naphthalene acetates case.

In August 1981, EPA published a Registration Standard for
"Naphthaleneacetic Acid its, Salts, Ester, and Acetamide." This document
described the uses and established the data requirements to reregister
the six supported naphthalene acetates. Tolerances were established for
NAA in/on apples, pears, quinces, olives, and pineapples (as the sodium
salt); for the ethyl ester of NAA in/on apples, pears, and olives; and
for naphthaleneacetamide in/on apples and pears. Data Call-ins (DCIs)
were issued in October and November 1990 and October 1995. The 1990 DCIs
mainly restated data requirements of the Registration Standard. The 1995
DCI required data to discern post-application (reentry) occupational and
residential exposure.

#### Use Sites and Patterns

#### Use Sites 

-   Apples, pears, citrus, olives, and cherries.

-   Non-bearing fruit and nut trees, ornamental plants, and shade trees.

-   Residential uses to stimulate root growth (root dips and soil
    drench) and to control sprouts and sucker growth on non-bearing
    fruit and ornamental trees.

#### Use Patterns

-   Apples and pears represent approximately 95% of the total active
    ingredient used annually with all other registered use sites
    accounting for the remaining 5% of use.

-   Approximately 20,000 lbs of the naphthalene acetate active
    ingredients are applied annually in the U.S.

#### Health Effects 

#### Naphthalene acetates show low acute toxicity, are not mutagenic, and are not expected to be carcinogenic. 

#### In laboratory animal studies, the most common effect (acute or short-term) from high exposure to the naphthalene acetates is reduced body weight gain. 

#### High exposure chronic effects in animal studies include: vomiting, stomach lesions, and slight sinusoidal histiocytosis in the livers of males. 

#### No metabolites (break down substances) of toxicological concern have been identified.

#### Ecological Effects

-   Based on the limited data set available, EPA believes that the
    toxicity of naphthalene acetates is low to mammals, birds, aquatic
    organisms, and non-endangered, non-target plants.

-   Risks to terrestrial insects cannot be quantified, but the available
    data do not suggest a substantial potential for adverse effects.

-   The potential for effects to listed plants from the use of
    naphthalene acetates on olive trees has been refined to a very small
    geographic area. However, a species specific assessment for that
    area has not been completed.

#### 

#### Risk Summary

-   The acute and chronic dietary exposure estimates for naphthalene
    acetates are significantly below EPA's level of concern for all
    supported commodities.

-   High-end estimates of pesticide concentrations in drinking water
    (from surface or ground water) sources are low and do not pose risks
    of concern.

#### For the highest residential exposure scenario to naphthalene acetates, estimated dermal and inhalation exposure are low and do not pose risks of concern.

-   The acute and chronic aggregate risk assessments for naphthalene
    acetates include exposure from food and drinking water only. Both
    acute and chronic aggregate risks are not of concern; residential
    exposures are not aggregated because the toxicity endpoints selected
    for the dietary routes of exposure and those selected for
    residential exposures of the naphthalene acetates are not based on
    common effects.

-   Using screening level exposure parameters, all but one occupational
    handler scenario results in MOEs above the target Margin of Exposure
    (MOE of 100), and are not of concern using baseline personal
    protective equipment (PPE). For the one handler scenario of
    potential concern, when using refined exposure parameters reflecting
    crop specific use patterns, the MOEs are above 100 and no longer of
    concern.

-   Two occupational post-application reentry exposure scenarios were
    assessed for the naphthalene acetates. The MOEs for the two
    post-application exposure scenarios are well above the target MOE of
    100 on the day of application and, therefore, not of risk concern.

-   No measures are needed to mitigate risk to non-target species and
    non-endangered, non-target plants.

-   Through the Agency's screening-level ecological risk assessment, the
    potential for effects to listed plants from the use of naphthalene
    acetates on olive trees has been refined to a very small geographic
    area. However, a species specific assessment for that area has not
    been completed. Until such time as that assessment is completed, the
    Agency cannot draw any definitive conclusions regarding whether the
    naphthalene acetates have effects on listed plants that may be in
    the vicinity of olive trees grown in in certain counties in
    California.

#### Regulatory Conclusion

The Agency has determined that the naphthalene acetates are eligible for
reregistration provided that: (i) current data gaps and additional data
needs are addressed and (ii) the label changes outlined in this document
are adopted. Accordingly, should a registrant fail to implement any of
the label changes or other measures identified in this document, the
Agency may take further regulatory action for the naphthalene acetates.

#### 

#### 

#### For More Information

Electronic copies of the NAA RED Amendment and all supporting documents
are available in public docket EPA-HQ-OPP-2006-0507 located online in
the Federal Docket Management System (FDMS) at
[http://www.regulations.gov](http://www.regulations.gov/).

An electronic copy of the NAA RED Amendment is also available on EPA's
pesticide reregistration status website at:
<http://www.epa.gov/pesticides/reregistration/status_page_n.html>.

For more information about EPA\'s pesticide reregistration program, the
NAA RED, or reregistration of individual products containing naphthalene
acetates, please contact the Special Review and Reregistration Division
(7508P), Office of Pesticide Programs, US EPA, Washington, DC 20460,
telephone 703-308-8000.

For information about the health effects of pesticides, or for
assistance in recognizing and managing pesticide poisoning symptoms,
please contact the National Pesticide Information Center (NPIC). Call
toll-free 1-800-858-7378, from 6:30 am to 4:30 am Pacific Time, or 9:30
am to 7:30 pm Eastern Standard Time, seven days a week. The NPIC
internet address is [http://npic.orst.edu](http://npic.orst.edu/).