Document ID: EPA-HQ-OPP-2010-0619-0004
Agency: epa
Document Type: Rule
Title: Pesticide Tolerances: Abamectin (avermectin)
Posted Date: 2011-11-09T05:00Z

[Federal Register Volume 76, Number 217 (Wednesday, November 9, 2011)]
[Rules and Regulations]
[Pages 69653-69659]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-28666]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2010-0619; FRL-8890-2]

Abamectin (avermectin); Pesticide Tolerances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes tolerances for residues of 
abamectin (avermectin) in or on onion, bulb, subgroup 3-07A; chive, 
fresh leaves; chive, dried leaves; and bean, dry, seed. This regulation 
additionally removes time-limited tolerances on bean, lima, seed; and 
onion, bulb, as the tolerances will be superseded by permanent 
tolerance. Interregional Research Project Number 4 (IR-4) requested 
these tolerances under the Federal Food, Drug, and Cosmetic Act 
(FFDCA).

DATES: This regulation is effective November 9, 2011. Objections and 
requests for hearings must be received on or before January 9, 2012, 
and must be filed in accordance with the instructions provided in 40 
CFR part 178 (see also Unit I.C. of the SUPPLEMENTARY INFORMATION).

ADDRESSES: EPA has established a docket for this action under docket 
identification (ID) number EPA-HQ-OPP-2010-0619. All documents in the 
docket are listed in the docket index available at http://www.regulations.gov. Although listed in the index, some information is 
not publicly available, e.g., Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. Certain 
other material, such as copyrighted material, is not placed on the 
Internet and will be publicly available only in hard copy form. 
Publicly available docket materials are available in the electronic 
docket at http://www.regulations.gov, or, if only available in hard 
copy, at the OPP Regulatory Public Docket in Rm. S-4400, One Potomac 
Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The Docket 
Facility is open from 8:30 a.m. to 4 p.m., Monday through Friday, 
excluding legal holidays. The Docket Facility telephone number is (703) 
305-5805.

FOR FURTHER INFORMATION CONTACT: Laura Nollen, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 305-7390; email address: nollen.laura@epa.gov.

SUPPLEMENTARY INFORMATION: 

I. General Information

A. Does this action apply to me?

    You may be potentially affected by this action if you are an 
agricultural producer, food manufacturer, or pesticide manufacturer. 
Potentially affected entities may include, but are not limited to those 
engaged in the following activities:
     Crop production (NAICS code 111).
     Animal production (NAICS code 112).
     Food manufacturing (NAICS code 311).
     Pesticide manufacturing (NAICS code 32532).
    This listing is not intended to be exhaustive, but rather to 
provide a guide for readers regarding entities likely to be affected by 
this action. Other types of entities not listed in this unit could also 
be affected. The North American Industrial Classification System 
(NAICS) codes have been provided to assist you and others in 
determining whether this action might apply to certain entities. If you 
have any questions regarding the applicability of this action to a 
particular entity, consult the person listed under FOR FURTHER 
INFORMATION CONTACT.

B. How can I get electronic access to other related information?

    You may access a frequently updated electronic version of EPA's 
tolerance regulations at 40 CFR part 180 through the Government 
Printing Office's e-CFR site at http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?&c=ecfr&tpl=/ecfrbrowse/Title40/40tab_02.tpl.

C. How can I file an objection or hearing request?

    Under FFDCA section 408(g), 21 U.S.C. 346a, any person may file an 
objection to any aspect of this regulation and may also request a 
hearing on those objections. You must file your objection or request a 
hearing on this regulation in accordance with the instructions provided 
in 40 CFR part 178. To ensure proper receipt by EPA, you must identify 
docket ID number EPA-HQ-OPP-2010-0619 in the subject line on the first 
page of your submission. All objections and requests for a hearing must 
be in writing, and must be received by the Hearing Clerk on or before 
January 9, 2012. Addresses for mail and hand delivery of objections and 
hearing requests are provided in 40 CFR 178.25(b).
    In addition to filing an objection or hearing request with the 
Hearing Clerk as described in 40 CFR part 178, please submit a copy of 
the filing that does not contain any CBI for inclusion in the public 
docket. Information not marked confidential pursuant to 40 CFR part 2 
may be disclosed publicly by EPA without prior notice. Submit a copy of 
your non-CBI objection or hearing request, identified by docket ID 
number EPA-HQ-OPP-2010-0619, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Bldg.), 2777 S. Crystal Dr., Arlington, VA. Deliveries are only 
accepted during the Docket Facility's normal hours of operation (8:30 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays). 
Special arrangements should be made for deliveries of boxed 
information. The Docket Facility telephone number is (703) 305-5805.

II. Summary of Petitioned-For Tolerance

    In the Federal Register of August 11, 2010 (75 FR 48667) (FRL-8840-
6), EPA issued a notice pursuant to section 408(d)(3) of FFDCA, 21 
U.S.C. 346a(d)(3), announcing the filing of a pesticide petition (PP 
0E7738) by IR-4, 500 College Rd. East, Suite 201W, Princeton, NJ 08540. 
The petition requested that 40 CFR 180.449 be amended by establishing 
tolerances for residues of the insecticide abamectin (avermectin 
B1), a mixture of avermectins containing greater than or 
equal to 80% avermectin B1a (5-O- demethyl avermectin 
A1) and less than or equal to 20% avermectin B1b 
(5-O-demethyl 25-de(1-methylpropyl)-25-(1-methylethyl) avermectin 
A1) and its delta-8,9-isomer, in or on bean, dry, seed at 
0.01 parts per million (ppm); chive, dried leaves at 0.07 ppm; chive, 
fresh leaves at 0.01 ppm; and onion, bulb, subgroup 3-07A at 0.01 ppm. 
That notice referenced a summary of the petition prepared on behalf of 
IR-4 by Syngenta Crop Protection, Inc., the registrant, which is 
available in the docket, http://www.regulations.gov. There were no 
comments received in response to the notice of filing.

[[Page 69654]]

    Based upon review of the data supporting the petition, EPA has 
revised the proposed tolerance for chive, dried leaves. Additionally, 
the Agency has revised the tolerance expression for all established 
commodities to be consistent with current Agency policy. The reasons 
for these changes are explained in Unit IV.C.

III. Aggregate Risk Assessment and Determination of Safety

    Section 408(b)(2)(A)(i) of FFDCA allows EPA to establish a 
tolerance (the legal limit for a pesticide chemical residue in or on a 
food) only if EPA determines that the tolerance is ``safe.'' Section 
408(b)(2)(A)(ii) of FFDCA defines ``safe'' to mean that ``there is a 
reasonable certainty that no harm will result from aggregate exposure 
to the pesticide chemical residue, including all anticipated dietary 
exposures and all other exposures for which there is reliable 
information.'' This includes exposure through drinking water and in 
residential settings, but does not include occupational exposure. 
Section 408(b)(2)(C) of FFDCA requires EPA to give special 
consideration to exposure of infants and children to the pesticide 
chemical residue in establishing a tolerance and to ``ensure that there 
is a reasonable certainty that no harm will result to infants and 
children from aggregate exposure to the pesticide chemical residue.* * 
*''
    Consistent with section 408(b)(2)(D) of FFDCA, and the factors 
specified in section 408(b)(2)(D) of FFDCA, EPA has reviewed the 
available scientific data and other relevant information in support of 
this action. EPA has sufficient data to assess the hazards of and to 
make a determination on aggregate exposure for abamectin (avermectin) 
including exposure resulting from the tolerances established by this 
action. EPA's assessment of exposures and risks associated with 
abamectin (avermectin) follows.

A. Toxicological Profile

    EPA has evaluated the available toxicity data and considered its 
validity, completeness, and reliability as well as the relationship of 
the results of the studies to human risk. EPA has also considered 
available information concerning the variability of the sensitivities 
of major identifiable subgroups of consumers, including infants and 
children.
    Abamectin (avermectin) has moderate to high acute toxicity by the 
oral route, high acute toxicity by the inhalation route, and low acute 
toxicity by the dermal route. It is slightly irritating to the skin, 
but is not an ocular irritant or a dermal sensitizer. The main target 
organ for abamectin (avermectin) is the nervous system. Neurotoxicity 
and developmental effects were detected in multiple studies and species 
of test animals. Signs of neurotoxicity were reported in studies of 
rats, mice, and dog and included decreases in foot splay reflex, 
mydriasis, curvature of the spine, decreased fore- and hind-limb grip 
strength, tip-toe gate, tremors, ataxia, or spastic movements of the 
limbs. Decreased body weight was also one of the most frequent 
findings. Severe effects, including death and morbid sacrifice, were 
noted in studies with rats and mice following repeated exposures.
    Increased qualitative and/or quantitative susceptibility was seen 
in prenatal developmental toxicity studies in mice and rabbits, and the 
reproductive toxicity and developmental neurotoxicity studies in rats. 
Developmental data indicate that the most sensitive effect of abamectin 
(avermectin) on fetuses is the increase in the incidence of cleft 
palates in mice and rabbits in the presence of no or minimal maternal 
toxicity. No maternal or developmental toxicity was seen in the 
prenatal developmental toxicity study in rats.
    The rat reproductive toxicity studies (two 1-generation 
reproduction studies and a 2-generation reproduction study) noted 
decreased pup body weights and/or survival at lower dose levels than 
those that caused parental toxicity. The developmental neurotoxicity 
studies in rats noted pup mortality and/or decreased body weights in 
the absence of maternal toxicity; there were no signs of neurotoxicity 
noted. In both the rat reproduction and a developmental neurotoxicity 
study, the data clearly indicated that the decrease in pup body weight 
seen at one dose level rapidly progressed to death at the next higher 
tested dose level. Oncogenicity and mutagenicity studies provide no 
indication that abamectin (avermectin) is carcinogenic or mutagenic; 
abamection (avermectin) has been classified as ``not likely to be 
carcinogenic to humans.''
    Specific information on the studies received and the nature of the 
adverse effects caused by abamectin (avermectin) as well as the no-
observed-adverse-effect-level (NOAEL) and the lowest-observed-adverse-
effect-level (LOAEL) from the toxicity studies can be found at http://www.regulations.gov in document: ``Abamectin. Human Health Risk 
Assessment for Proposed Uses on the Bulb Onion Subgroup 3-07A, Chives, 
and Dry Beans,'' pp. 54-58 in docket ID number EPA-HQ-OPP-2010-0619.

B. Toxicological Points of Departure/Levels of Concern

    Once a pesticide's toxicological profile is determined, EPA 
identifies toxicological points of departure (POD) and levels of 
concern to use in evaluating the risk posed by human exposure to the 
pesticide. For hazards that have a threshold below which there is no 
appreciable risk, the toxicological POD is used as the basis for 
derivation of reference values for risk assessment. PODs are developed 
based on a careful analysis of the doses in each toxicological study to 
determine the dose at which the NOAEL and the LOAEL. Uncertainty/safety 
factors are used in conjunction with the POD to calculate a safe 
exposure level--generally referred to as a population-adjusted dose 
(PAD) or a reference dose (RfD)--and a safe margin of exposure (MOE). 
For non-threshold risks, the Agency assumes that any amount of exposure 
will lead to some degree of risk. Thus, the Agency estimates risk in 
terms of the probability of an occurrence of the adverse effect 
expected in a lifetime. For more information on the general principles 
EPA uses in risk characterization and a complete description of the 
risk assessment process, see http://www.epa.gov/pesticides/factsheets/riskassess.htm.
    A summary of the toxicological endpoints for abamectin (avermectin) 
used for human risk assessment is shown in Table 1 of this unit.

[[Page 69655]]

  Table 1--Summary of Toxicological Doses and Endpoints for Abamectin (Avermectin) for Use in Human Health Risk
                                                   Assessment
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                                     Point of departure and
         Exposure/Scenario             uncertainty/safety    RfD, PAD, LOC for risk    Study and toxicological
                                             factors               assessment                  effects
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Acute dietary (General population    NOAEL = 0.5 mg/kg/day.  Acute RfD = 0.005 mg/   12-Week dose-range finding
 including infants and children).    UFA = 10x.............   kg/day.                 study in dogs
                                     UFH = 10x FQPA SF = 1x  aPAD = 0.005 mg/kg/day  LOAEL = 1.0 mg/kg/day based
                                                                                      on mydriasis seen 1-5
                                                                                      times during the first
                                                                                      week of treatment; Acute
                                                                                      neurotoxicity study in
                                                                                      rats
                                                                                     LOAEL = 1.5 mg/kg/day based
                                                                                      on increased incidence of
                                                                                      foot splay.
Chronic dietary (All populations)..  NOAEL= 0.12 mg/kg/day.  Chronic RfD = 0.0012    Combined data: Three rat
                                     UFA = 10x.............   mg/kg/day.              reproduction studies and
                                     UFH = 10x.............  cPAD = 0.0004 mg/kg/     two rat developmental
                                     FQPA SF = 3x..........   day.                    neurotoxicity studies
                                                                                     LOAEL = 0.2 mg/kg/day based
                                                                                      on decreased pup body
                                                                                      weight in pups at 0.2 mg/
                                                                                      kg/day.
Incidental oral short- and           NOAEL= 0.12 mg/kg/day.  LOC for MOE = 300.....  Combined data: Three rat
 intermediate-term (1 to 30 days     UFA = 10x.............                           reproduction studies and
 and 1 to 6 months).                 UFH = 10x.............                           two rat developmental
                                     FQPA SF = 3x..........                           neurotoxicity studies
                                                                                     LOAEL = 0.2 mg/kg/day based
                                                                                      on decreased pup body
                                                                                      weight.
Dermal (all durations).............  Dermal (or oral) study  LOC for MOE = 300.....  Combined data: Three rat
                                     NOAEL = 0.12 mg/kg/day                           reproduction studies and
                                     UFA = 10x.............                           two rat developmental
                                     UFH = 10x.............                           neurotoxicity studies
                                     FQPA SF = 3x..........                          LOAEL = 0.2 mg/kg/day based
                                                                                      on decreased pup body
                                                                                      weight.
Inhalation (all durations).........  Dermal (or oral) study  LOC for MOE = 300.....  Combined data: Three rat
                                     NOAEL = 0.12 mg/kg/day                           reproduction studies and
                                     UFA = 10x.............                           two rat developmental
                                     UFH = 10x.............                           neurotoxicity studies
                                     FQPA SF = 3x..........                          LOAEL = 0.2 mg/kg/day based
                                                                                      on decreased pup body
                                                                                      weight.
                                    ----------------------------------------------------------------------------
Cancer (Oral, dermal, inhalation)..      ``Not likely to be carcinogenic to humans'' based on the absence of
                                            significant increase in tumor incidence in two adequate rodent
                                                               carcinogenicity studies.
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UFA = extrapolation from animal to human (interspecies). UFH = potential variation in sensitivity among members
  of the human population (intraspecies). FQPA SF = Food Quality Protection Act Safety Factor. PAD = population
  adjusted dose (a = acute, c = chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of
  concern.

C. Exposure Assessment

    1. Dietary exposure from food and feed uses. In evaluating dietary 
exposure to abamectin (avermectin), EPA considered exposure under the 
petitioned-for tolerances as well as all existing abamectin 
(avermectin) tolerances in 40 CFR 180.449. EPA assessed dietary 
exposures from abamectin (avermectin) in food as follows:
    i. Acute exposure. Quantitative acute dietary exposure and risk 
assessments are performed for a food-use pesticide, if a toxicological 
study has indicated the possibility of an effect of concern occurring 
as a result of a 1-day or single exposure.
    Such effects were identified for abamectin (avermectin). In 
estimating acute dietary exposure, EPA used food consumption 
information from the United States Department of Agriculture (USDA) 
1994-1996 and 1998 Nationwide Continuing Surveys of Food Intake by 
Individuals (CSFII). As to residue levels in food, EPA utilized 
tolerance level residues for the proposed crops and okra and 
anticipated residues for the remaining commodities. Empirical 
processing factors and percent crop treated (PCT) data were also used, 
when available.
    ii. Chronic exposure. In conducting the chronic dietary exposure 
assessment EPA used the food consumption data from the USDA 1994-1996 
and 1998 CSFII. As to residue levels in food, EPA utilized tolerance 
level residues for the proposed crops and okra, and average residues 
from field trials for the remaining crops. Empirical processing factors 
and PCT were also used, when available.
    iii. Cancer. Based on the data summarized in Unit III.A., EPA has 
concluded that abamectin (avermectin) does not pose a cancer risk to 
humans. Therefore, a dietary exposure assessment for the purpose of 
assessing cancer risk is unnecessary.
    iv. Anticipated residue and PCT information. Section 408(b)(2)(E) 
of FFDCA authorizes EPA to use available data and information on the 
anticipated residue levels of pesticide residues in food and the actual 
levels of pesticide residues that have been measured in food. If EPA 
relies on such information, EPA must require pursuant to FFDCA section 
408(f)(1) that data be provided 5 years after the tolerance is 
established, modified, or left in effect, demonstrating that the levels 
in food are not above the levels anticipated. For the present action, 
EPA will issue such data call-ins as are required by FFDCA section 
408(b)(2)(E) and authorized under FFDCA section 408(f)(1). Data will be 
required to be submitted no later than 5 years from the date of 
issuance of these tolerances.
    Section 408(b)(2)(F) of FFDCA states that the Agency may use data 
on the actual percent of food treated for assessing chronic dietary 
risk only if:
     Condition A: The data used are reliable and provide a 
valid basis to show what percentage of the food derived from such crop 
is likely to contain the pesticide residue.
     Condition B: The exposure estimate does not underestimate 
exposure for any significant subpopulation group.
     Condition C: Data are available on pesticide use and food 
consumption in a particular area, the exposure estimate does not 
understate exposure for the population in such area.
    In addition, the Agency must provide for periodic evaluation of any 
estimates used. To provide for the periodic evaluation of the estimate 
of PCT as required by FFDCA section 408(b)(2)(F), EPA may require 
registrants to submit data on PCT.
    For the acute dietary assessment, the maximum PCT for existing uses 
were estimated as follows:

[[Page 69656]]

    Almonds, 75%; apples, 10%; apricots, 5%; avocados, 60%; 
cantaloupes, 30%; celery, 65%; cherries, 2.5%; cotton, 20%; cucumbers, 
10%; grapefruit, 80%; grapes, 25%; honeydew, 35%; lemons, 55%; lettuce, 
20%; oranges, 45%; peaches, 2.5%; pears, 80%; pecans, 2.5%; peppers, 
25%; potatoes, 2.5%; prunes, 10%; pumpkins, 10%; spinach, 45%; squash, 
10%; strawberries, 45%; tangerines, 65%; tomatoes, 20%; walnuts, 20%; 
and watermelons, 10%.
    For the chronic dietary assessment, the average PCT for existing 
uses were estimated as follows:
    Almonds, 50%; apples, 5%; apricots, 5%; avocados, 40%; cantaloupes, 
15%; celery, 40%; cherries, 1%; cotton, 5%; cucumbers, 5%; grapefruit, 
60%; grapes, 10%; honeydew, 20%; lemons, 35%; lettuce, 10%; oranges, 
25%; peaches, 1%; pears, 70%; pecans, 1%; peppers, 10%; potatoes, 1%; 
prunes, 2.5%; pumpkins, 2.5%; spinach, 20%; squash, 5%; strawberries, 
30%; tangerines, 60%; tomatoes, 10%; walnuts, 10%; and watermelons, 5%.
    In most cases, EPA uses available data from United States 
Department of Agriculture/National Agricultural Statistics Service 
(USDA/NASS), proprietary market surveys, and the National Pesticide Use 
Database for the chemical/crop combination for the most recent 6-7 
years. EPA uses an average PCT for chronic dietary risk analysis. The 
average PCT figure for each existing use is derived by combining 
available public and private market survey data for that use, averaging 
across all observations, and rounding to the nearest 5%, except for 
those situations in which the average PCT is less than one. In those 
cases, 1% is used as the average PCT and 2.5% is used as the maximum 
PCT. EPA uses a maximum PCT for acute dietary risk analysis. The 
maximum PCT figure is the highest observed maximum value reported 
within the recent 6 years of available public and private market survey 
data for the existing use and rounded up to the nearest multiple of 5%.
    The Agency believes that the three conditions discussed in Unit 
III.C.1.iv. have been met. With respect to Condition A, PCT estimates 
are derived from Federal and private market survey data, which are 
reliable and have a valid basis. The Agency is reasonably certain that 
the percentage of the food treated is not likely to be an 
underestimation. As to Conditions B and C, regional consumption 
information and consumption information for significant subpopulations 
is taken into account through EPA's computer-based model for evaluating 
the exposure of significant subpopulations including several regional 
groups. Use of this consumption information in EPA's risk assessment 
process ensures that EPA's exposure estimate does not understate 
exposure for any significant subpopulation group and allows the Agency 
to be reasonably certain that no regional population is exposed to 
residue levels higher than those estimated by the Agency. Other than 
the data available through national food consumption surveys, EPA does 
not have available reliable information on the regional consumption of 
food to which abamectin (avermectin) may be applied in a particular 
area.
    2. Dietary exposure from drinking water. The Agency used screening 
level water exposure models in the dietary exposure analysis and risk 
assessment for abamectin (avermectin) in drinking water. These 
simulation models take into account data on the physical, chemical, and 
fate/transport characteristics of abamectin (avermectin). Further 
information regarding EPA drinking water models used in pesticide 
exposure assessment can be found at http://www.epa.gov/oppefed1/models/water/index.htm.
    Based on the Pesticide Root Zone Model/Exposure Analysis Modeling 
System (PRZM/EXAMS) and Screening Concentration in Ground Water (SCI-
GROW) models, the estimated drinking water concentrations (EDWCs) of 
abamectin (avermectin) for acute exposures are estimated to be 2.3 
parts per billion (ppb) for surface water and 1.6 x 10-\3\ 
ppb for ground water, and for chronic exposures for non-cancer 
assessments are estimated to be 1.3 ppb for surface water and 1.6 x 
10-\3\ ppb for ground water.
    Modeled estimates of drinking water concentrations were directly 
entered into the dietary exposure model. For acute dietary risk 
assessment, the water concentration value of 2.3 ppb was used to assess 
the contribution to drinking water. For chronic dietary risk 
assessment, the water concentration of value 1.3 ppb was used to assess 
the contribution to drinking water.
    3. From non-dietary exposure. The term ``residential exposure'' is 
used in this document to refer to non-occupational, non-dietary 
exposure (e.g., for lawn and garden pest control, indoor pest control, 
termiticides, and flea and tick control on pets).
    Abamectin (avermectin) is currently registered for the following 
uses that could result in residential handler and postapplication 
exposures: Granular baits used to treat lawns and indoor crack and 
crevice dust products. EPA assessed residential exposure using the 
following assumptions: Adults were assessed for short- and 
intermediate-term residential handler and postapplication exposures 
(dermal and inhalation). Children were assessed for short- and 
intermediate-term postapplication dermal, inhalation, and incidental 
ingestion exposures (hand-to-mouth and object-to-mouth). Recreational 
exposures to turf are expected to be similar to, or less than, those 
described above, and were therefore not assessed. Further information 
regarding EPA standard assumptions and generic inputs for residential 
exposures may be found at http://www.epa.gov/pesticides/trac/science/trac6a05.pdf.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of FFDCA requires that, when 
considering whether to establish, modify, or revoke a tolerance, the 
Agency consider ``available information'' concerning the cumulative 
effects of a particular pesticide's residues and ``other substances 
that have a common mechanism of toxicity.'' EPA has not found abamectin 
(avermectin) to share a common mechanism of toxicity with any other 
substances, and abamectin (avermectin) does not appear to produce a 
toxic metabolite produced by other substances. For the purposes of this 
tolerance action, therefore, EPA has assumed that abamectin 
(avermectin) does not have a common mechanism of toxicity with other 
substances. For information regarding EPA's efforts to determine which 
chemicals have a common mechanism of toxicity and to evaluate the 
cumulative effects of such chemicals, see EPA's Web site at http://www.epa.gov/pesticides/cumulative.

D. Safety Factor for Infants and Children

    1. In general. Section 408(b)(2)(C) of FFDCA provides that EPA 
shall apply an additional tenfold (10X) margin of safety for infants 
and children in the case of threshold effects to account for prenatal 
and postnatal toxicity and the completeness of the database on toxicity 
and exposure unless EPA determines based on reliable data that a 
different margin of safety will be safe for infants and children. This 
additional margin of safety is commonly referred to as the FQPA Safety 
Factor (SF). In applying this provision, EPA either retains the default 
value of 10X, or uses a different additional safety factor when 
reliable data available to EPA support the choice of a different 
factor.
    2. Prenatal and postnatal sensitivity. The abamectin (avermectin) 
toxicity database is adequate to evaluate

[[Page 69657]]

potential increased susceptibility of infants and children, and 
includes developmental toxicity studies in rat, mice, and rabbits; two 
1-generation rat reproductive toxicity studies in rat; a 2-generation 
reproductive toxicity study in rat; and two developmental neurotoxicity 
studies in rat. No developmental effects were seen in the rat 
developmental toxicity study. However, increased quantitative 
susceptibility was noted in the prenatal developmental toxicity studies 
in mice and rabbits, the rat reproductive toxicity studies, and the 
developmental neurotoxicity studies in rat.
    3. Conclusion. In previous abamectin (avermectin) risk assessments, 
the 10x FQPA safety factor was retained as a database uncertainty 
factor for the lack of a developmental neurotoxicity study. Two 
developmental neurotoxicity studies have now been submitted and 
reviewed and the findings in these studies were considered in the 
identification of toxicological points of departure and uncertainty/
safety factors.
    EPA has determined that reliable data show the safety of infants 
and children would be adequately protected if the FQPA SF were reduced 
to 1X for the acute dietary assessment and 3X for all assessments other 
than acute dietary. That decision is based on the following findings:
    i. For all risk assessments involving repeated exposures to 
abamectin (avermectin), EPA determined that a 3x safety factor would be 
appropriate, based on the severity of effects (decrease in pup body 
weight and mortality) and the steepness of the dose-response curve seen 
in the developmental neurotoxicity study and three reproductive 
toxicity studies in the rat. These studies have documented a very 
narrow dose range from NOAEL (0.12 mg/kg/day) to adverse effect (0.2 
mg/kg/day) to severe adverse effect (0.4 mg/kg/day). Dose spacing is 
commonly greater than 2x between NOAEL and LOAEL, and the 3x difference 
between the NOAEL and the dose that induced mortality in the pups in 
the developmental neurotoxicity study provides little margin of safety 
for the severity of the effects seen.
    Retaining an additional 3x FQPA safety factor effectively provides 
a 10x margin between the dose which causes death (0.4 mg/kg/day) and 
the NOAEL adjusted by the additional safety factor (0.12 mg/kg/day/3x = 
0.04 mg/kg/day). A dose spacing of 10x between a NOAEL and LOAEL is as 
broad, if not broader, than the dose spacing generally used in animal 
testing and thus removes the residual concern of the steepness of the 
dose-response curve and the severe effects noted.
    Additionally, this adjusted point of departure (0.04 mg/kg/day) 
would address the concerns for the increased susceptibility seen at 
higher doses in the 2-generation reproduction study in rats (LOAEL = 
0.4 mg/kg/day), prenatal developmental study in mice (LOAEL = 0.75 mg/
kg/day), the prenatal developmental toxicity study in rabbits (LOAEL = 
2 mg/kg/day), and the 1-generation rat reproduction study (LOAEL = 0.2 
mg/kg/day).
    With respect to acute dietary exposure, the endpoint selected for 
risk assessment is based on mydriasis observed in dogs. The EPA 
determined that the additional 3x factor applied to chronic and other 
exposure scenarios is not applicable to acute exposure for the 
following reasons:
    a. The concerns noted for steepness of the dose-response curve and 
the severity of effects were not seen in the studies where mydriasis 
occurred.
    b. The reduced body weights noted in studies following repeated 
exposure to abamectin (avermectin) are not a single dose effect.
    c. The increased susceptibility seen in the prenatal developmental 
toxicity studies, reproductive toxicity studies, and the developmental 
neurotoxicity studies were seen at a dose lower (LOAEL 0.2 mg/kg/day) 
than the dose (LOAEL 1.0 mg/kg/day) that caused mydriasis.
    Therefore, EPA has determined that it would be appropriate if the 
FQPA SF were reduced to 1X for the acute dietary assessment.
    ii. The toxicity database for abamectin (avermectin) is complete, 
except for immunotoxicity testing. Recent changes to 40 CFR part 158 
imposed new data requirements for immunotoxicity testing (OPPTS 
Guideline 870.7800) for pesticide registration. However, the toxicity 
database for abamectin (avermectin) provides no indication of 
immunotoxicity and abamectin (avermectin) does not belong to a class of 
chemicals that would be expected to be immunotoxic. EPA does not 
believe that conducting an immunotoxicity study will result in a NOAEL 
less than the NOAELs of 0.5 mg/kg/day and 0.12 mg/kg/day already set 
for abamectin (avermectin) acute and repeated exposures, respectively, 
and an additional uncertainty factor is not needed to account for 
potential immunotoxicity.
    iii. Signs of neurotoxicity ranging from decrease in foot splay 
reflex, mydriasis (i.e., excessive dilation of the pupil), curvature of 
the spine, decreased fore- and hind-limb grip strength, tip-toe gate, 
tremors, ataxia, or spastic movements of the limbs were reported in 
various studies with different durations of abamectin (avermectin) 
exposure in rats, mice, and dogs. However, the results of two submitted 
rat developmental neurotoxicity studies did not show any evidence of 
neurotoxicity.
    iv. There are no residual uncertainties identified in the exposure 
databases. The acute and chronic dietary exposure assessments were 
refined and utilized tolerance level or anticipated residues, default 
or empirical processing factors, and PCT estimates. EPA made 
conservative (protective) assumptions in the ground and surface water 
modeling used to assess exposure to abamectin (avermectin) in drinking 
water. EPA used similarly conservative assumptions to assess 
postapplication exposure of children as well as incidental oral 
exposure of toddlers. These assessments will not underestimate the 
exposure and risks posed by abamectin (avermectin).

E. Aggregate Risks and Determination of Safety

    EPA determines whether acute and chronic dietary pesticide 
exposures are safe by comparing aggregate exposure estimates to the 
acute PAD (aPAD) and chronic PAD (cPAD). For linear cancer risks, EPA 
calculates the lifetime probability of acquiring cancer given the 
estimated aggregate exposure. Short-, intermediate-, and chronic-term 
risks are evaluated by comparing the estimated aggregate food, water, 
and residential exposure to the appropriate PODs to ensure that an 
adequate MOE exists.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to abamectin (avermectin) will occupy 30% of the aPAD for infants less 
than 1 year old, the population group receiving the greatest exposure.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that chronic exposure to 
abamectin (avermectin) from food and water will utilize 50% of the cPAD 
for children 1-2 years old the population group receiving the greatest 
exposure. Based on the explanation in Unit III.C.3., regarding 
residential use patterns, chronic residential exposure to residues of 
abamectin (avermectin) is not expected.
    3. Short- and intermediate-term risk. Short- and intermediate-term 
aggregate exposure takes into account short- and intermediate-term 
residential exposure plus chronic exposure to food and water

[[Page 69658]]

(considered to be a background exposure level). Abamectin (avermectin) 
is currently registered for uses that could result in short- and 
intermediate-term residential exposures, and the Agency has determined 
that it is appropriate to aggregate chronic exposure through food and 
water with short- and intermediate-term residential exposures to 
abamectin (avermectin).
    Using the exposure assumptions described in this unit for short- 
and intermediate-term exposures, EPA has concluded the combined short- 
and intermediate-term food, water, and residential exposures result in 
aggregate MOEs of 1200 for the general population and 500 for children 
1-2 years old. Because EPA's level of concern for abamectin 
(avermectin) is a MOE of 300 or below, these MOEs are not of concern.
    4. Aggregate cancer risk for U.S. population. Based on the lack of 
evidence of carcinogenicity in two adequate rodent carcinogenicity 
studies, abamectin (avermectin) is not expected to pose a cancer risk 
to humans.
    5. Determination of safety. Based on these risk assessments, EPA 
concludes that there is a reasonable certainty that no harm will result 
to the general population, or to infants and children from aggregate 
exposure to abamectin (avermectin) residues.

IV. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodologies are available in Pesticide 
Analytical Manual II (PAM II) for citrus and processed fractions 
(Method I), ginned cottonseed (Method IA), and bovine tissues and milk 
(Method II). Additionally, Method M-073 and M-936-95-2 have been 
validated by the Agency and submitted for inclusion in PAM II as 
enforcement methods. These five methods are adequate for enforcement of 
the tolerances on plants and livestock.
    Method M-073 and M-936-95-2 may be requested from: Chief, 
Analytical Chemistry Branch, Environmental Science Center, 701 Mapes 
Rd., Ft. Meade, MD 20755-5350; telephone number: (410) 305-2905; email 
address: residuemethods@epa.gov.

B. International Residue Limits

    In making its tolerance decisions, EPA seeks to harmonize U.S. 
tolerances with international standards whenever possible, consistent 
with U.S. food safety standards and agricultural practices. EPA 
considers the international maximum residue limits (MRLs) established 
by the Codex Alimentarius Commission (Codex), as required by FFDCA 
section 408(b)(4). The Codex Alimentarius is a joint U.N. Food and 
Agriculture Organization/World Health Organization food standards 
program, and it is recognized as an international food safety 
standards-setting organization in trade agreements to which the United 
States is a party. EPA may establish a tolerance that is different from 
a Codex MRL; however, FFDCA section 408(b)(4) requires that EPA explain 
the reasons for departing from the Codex level.
    There are currently no Codex MRLs for abamectin (avermectin) on 
commodities associated with this petition.

C. Revisions to Petitioned-For Tolerances

    Based upon review of the data supporting the petition, EPA revised 
the proposed tolerance for chive, dried leaves from 0.07 ppm to 0.02 
ppm. EPA revised the tolerance level based on analysis of the residue 
field trial data using the Agency's Tolerance Spreadsheet in accordance 
with the Agency's Guidance for Setting Pesticide Tolerances Based on 
Field Trial Data. Additionally, the Agency has revised the tolerance 
expression to clarify:
    1. That, as provided in FFDCA section 408(a)(3), the tolerance 
covers metabolites and degradates of abamectin (avermectin) not 
specifically mentioned; and
    2. That compliance with the specified tolerance levels is to be 
determined by measuring only the specific compounds mentioned in the 
tolerance expression.

V. Conclusion

    Therefore, tolerances are established for residues of abamectin 
(avermectin), avermectin B1 [a mixture of avermectins 
containing greater than or equal to 80% avermectin B1a (5-O-
demethyl avermectin A1) and less than or equal to 20% 
avermectin B1b (5-O-demethyl-25-de(1-methylpropyl)-25-(1-
methylethyl) avermectin A1)] and its delta-8,9-isomer, in or 
on onion, bulb, subgroup 3-07A at 0.01 ppm; chive, fresh leaves at 0.01 
ppm; chive, dried leaves at 0.02 ppm; and bean, dry, seed at 0.01 ppm. 
This regulation additionally removes the time-limited tolerances on 
bean, lima, seed at 0.005 ppm; and onion, bulb at 0.005 ppm, as they 
will be superseded by permanent tolerances.

VI. Statutory and Executive Order Reviews

    This final rule establishes tolerances under section 408(d) of 
FFDCA in response to a petition submitted to the Agency. The Office of 
Management and Budget (OMB) has exempted these types of actions from 
review under Executive Order 12866, entitled Regulatory Planning and 
Review (58 FR 51735, October 4, 1993). Because this final rule has been 
exempted from review under Executive Order 12866, this final rule is 
not subject to Executive Order 13211, entitled Actions Concerning 
Regulations That Significantly Affect Energy Supply, Distribution, or 
Use (66 FR 28355, May 22, 2001) or Executive Order 13045, entitled 
Protection of Children from Environmental Health Risks and Safety Risks 
(62 FR 19885, April 23, 1997). This final rule does not contain any 
information collections subject to OMB approval under the Paperwork 
Reduction Act (PRA), 44 U.S.C. 3501 et seq., nor does it require any 
special considerations under Executive Order 12898, entitled Federal 
Actions to Address Environmental Justice in Minority Populations and 
Low-Income Populations (59 FR 7629, February 16, 1994).
    Since tolerances and exemptions that are established on the basis 
of a petition under section 408(d) of FFDCA, such as the tolerance in 
this final rule, do not require the issuance of a proposed rule, the 
requirements of the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et 
seq.) do not apply.
    This final rule directly regulates growers, food processors, food 
handlers, and food retailers, not States or tribes, nor does this 
action alter the relationships or distribution of power and 
responsibilities established by Congress in the preemption provisions 
of section 408(n)(4) of FFDCA. As such, the Agency has determined that 
this action will not have a substantial direct effect on States or 
tribal governments, on the relationship between the national government 
and the States or tribal governments, or on the distribution of power 
and responsibilities among the various levels of government or between 
the Federal Government and Indian tribes. Thus, the Agency has 
determined that Executive Order 13132, entitled Federalism (64 FR 
43255, August 10, 1999) and Executive Order 13175, entitled 
Consultation and Coordination with Indian Tribal Governments (65 FR 
67249, November 9, 2000) do not apply to this final rule. In addition, 
this final rule does not impose any enforceable duty or contain any 
unfunded mandate as described under Title II of the Unfunded Mandates 
Reform Act of 1995 (UMRA) (Pub. L. 104-4).
    This action does not involve any technical standards that would 
require Agency consideration of voluntary consensus standards pursuant 
to section 12(d) of the National Technology

[[Page 69659]]

Transfer and Advancement Act of 1995 (NTTAA), Public Law 104-113, 
section 12(d) (15 U.S.C. 272 note).

VII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report to each House of the Congress and to 
the Comptroller General of the United States. EPA will submit a report 
containing this rule and other required information to the U.S. Senate, 
the U.S. House of Representatives, and the Comptroller General of the 
United States prior to publication of this final rule in the Federal 
Register. This final rule is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 180

    Environmental protection, Administrative practice and procedure, 
Agricultural commodities, Pesticides and pests, Reporting and 
recordkeeping requirements.

    Dated: September 30, 2011.
Daniel J. Rosenblatt,
Acting Director, Registration Division, Office of Pesticide Programs.

    Therefore, 40 CFR chapter I is amended as follows:

PART 180--[AMENDED]

0
1. The authority citation for part 180 continues to read as follows:

    Authority:  21 U.S.C. 321(q), 346a and 371.

0
2. Section 180.449 is amended in paragraph (a) by revising the 
introductory text and alphabetically adding the following commodities 
to the table and by revising paragraph (b) to read as follows:

Sec.  180.449  Avermectin B1 and its delta-8,9-isomer; 
tolerances for residues.

    (a) General. Tolerances are established for residues of abamectin 
(avermectin), including its metabolites and degradates, in or on the 
commodities in the following table. Compliance with the tolerance 
levels specified in the following table is to be determined by 
measuring only avermectin B1 [a mixture of avermectins 
containing greater than or equal to 80% avermectin B1a (5-O-
demethyl avermectin A1) and less than or equal to 20% 
avermectin B1b (5-O-demethyl-25-de(1-methylpropyl)-25-(1-
methylethyl) avermectin A1)] and its delta-8,9-isomer in or 
on the following commodities:

------------------------------------------------------------------------
                                                              Parts per
                         Commodity                             million
------------------------------------------------------------------------
 
                                * * * * *
Bean, dry, seed...........................................          0.01
 
                                * * * * *
Chive, dried leaves.......................................          0.02
Chive, fresh leaves.......................................          0.01
 
                                * * * * *
Onion, bulb, subgroup 3-07A...............................          0.01
 
                                * * * * *
------------------------------------------------------------------------

     (b) Section 18 emergency exemptions. [Reserved]
* * * * *
[FR Doc. 2011-28666 Filed 11-8-11; 8:45 am]
BILLING CODE 6560-50-P