Naphthalene Acetic Acid, Its Salts, Ester and
Acetamide R.E.D. FACTS
November 7, 2007
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
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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 Ibs 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.
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• 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.requlations.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/rereqistration/status 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.
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