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

 

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   HYPERLINK
"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:     HYPERLINK
"http://www.epa.gov/pesticides/reregistration/status_page_n.html" 
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   HYPERLINK "http://npic.orst.edu" 
http://npic.orst.edu .

