Document ID: EPA-HQ-OPP-2006-0918-0001
Agency: epa
Document Type: Rule
Title: Avermectin; Pesticide Tolerances for Emergency Exemptions
Posted Date: 2007-02-07T05:00Z

[Federal Register: February 7, 2007 (Volume 72, Number 25)]
[Rules and Regulations]               
[Page 5624-5630]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07fe07-19]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[EPA-HQ-OPP-2006-0918; FRL-8110-8]

 
Avermectin; Pesticide Tolerances for Emergency Exemptions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This regulation establishes a time-limited tolerance for 
combined residues of the insecticide avermectin B1 and its 
delta-8,9-isomer in or on bulb onions. This action is in response to 
EPA's granting of an emergency exemption under section 18 of the 
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorizing 
use of this pesticide on bulb onions. This regulation establishes a 
maximum permissible level for residues of avermectin in this food 
commodity. The tolerance expires and is revoked on December 31, 2009.

DATES: This regulation is effective February 7, 2007. Objections and 
requests for hearings must be received on or before April 9, 2007, 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-2006-0918. All documents in the 
docket are listed on the regulations.gov website. 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 either in the electronic docket at http://www.regulations.gov
, or, if only available in hard copy, at the Office 

of Pesticide Programs (OPP) Regulatory Public Docket in Rm. S-4400, One 
Potomac Yard (South Building), 2777 S. Crystal Drive Arlington, VA. The 
hours of operation of this Docket Facility are from 8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays. The Docket 
telephone number is (703) 305-5805.

FOR FURTHER INFORMATION CONTACT: Andrew Ertman, Registration Division 
(7505P), Office of Pesticide Programs, Environmental Protection Agency, 
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone 
number: (703) 308-9367; e-mail address: ertman.andrew@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

[[Page 5625]]

affected entities may include, but are not limited to:
     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 provides 
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 Access Electronic Copies of this Document?

    In addition to accessing an electronic copy of this Federal 
Register document through the electronic docket at http://www.regulations.gov
, you may access this Federal Register document 

electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr. You may also access a 

frequently updated electronic version of 40 CFR part 180 through the 
Government Printing Office's pilot e-CFR site at http://www.gpoaccess.gov/ecfr
.

C. Can I File an Objection or Hearing Request?

    Under section 408(g) of the FFDCA, as amended by the FQPA, any 
person may file an objection to any aspect of this regulation and may 
also request a hearing on those objections. The EPA procedural 
regulations which govern the submission of objections and requests for 
hearings appear in 40 CFR part 178. 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-2006-0918 in the 
subject line on the first page of your submission. All requests must be 
in writing, and must be mailed or delivered to the Hearing Clerk on or 
before April 9, 2007.
    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 that is described in ADDRESSES. Information not marked 
confidential pursuant to 40 CFR part 2 may be disclosed publicly by EPA 
without prior notice. Submit your copies, identified by docket ID 
number EPA-HQ-OPP-2006-0918, 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 
Building), 2777 S. Crystal Drive, Arlington, VA. Deliveries are only 
accepted during the Docket'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 telephone number is (703) 305-5805.

II. Background and Statutory Findings

    EPA, on its own initiative, in accordance with sections 408(e) and 
408 (l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 
U.S.C. 346a, is establishing a time-limited tolerance for combined 
residues of the insecticide avermectin B1 and its delta-8,9-
isomer in or on bulb onions at 0.005 parts per million (ppm). This 
tolerance expires and is revoked on December 31, 2009. EPA will publish 
a document in the Federal Register to remove the revoked tolerance from 
the Code of Federal Regulations (CFR).
    Section 408(l)(6) of the FFDCA requires EPA to establish a time-
limited tolerance or exemption from the requirement for a tolerance for 
pesticide chemical residues in food that will result from the use of a 
pesticide under an emergency exemption granted by EPA under section 18 
of FIFRA. Such tolerances can be established without providing notice 
or period for public comment. EPA does not intend for its actions on 
section 18 related tolerances to set binding precedents for the 
application of section 408 of the FFDCA and the new safety standard to 
other tolerances and exemptions. Section 408(e) of the FFDCA allows EPA 
to establish a tolerance or an exemption from the requirement of a 
tolerance on its own initiative, i.e., without having received any 
petition from an outside party.
    Section 408(b)(2)(A)(i) of the 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 the 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 the 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. . . 
. 
    Section 18 of the FIFRA authorizes EPA to exempt any Federal or 
State agency from any provision of FIFRA, if EPA determines that 
``emergency conditions exist which require such exemption.'' This 
provision was not amended by the Food Quality Protection Act of 1996 
(FQPA). EPA has established regulations governing such emergency 
exemptions in 40 CFR part 166.

III. Emergency Exemption for Avermectin on Bulb Onions and FFDCA 
Tolerances

    EPA has authorized under FIFRA section 18 the use of avermectin on 
bulb onions for control of thrips in Colorado. Avermectin also goes by 
the name abamectin, but the two names describe the same chemical. The 
CAS number is the same for both (71751-41-2). After having reviewed the 
materials submitted in support of the emergency exemption request, EPA 
concurred with the applicant that emergency conditions existed for this 
State.
    As part of its assessment of this emergency exemption, EPA assessed 
the potential risks presented by residues of avermectin in or on bulb 
onions. In doing so, EPA considered the safety standard in section 
408(b)(2) of the FFDCA, and EPA decided that the necessary time-limited 
tolerance under section 408(l)(6) of the FFDCA would be consistent with 
the safety standard and with FIFRA section 18. Consistent with the need 
to move quickly on the emergency exemption in order to address an 
urgent non-routine situation and to ensure that the resulting food is 
safe and lawful, EPA is issuing this tolerance without notice and 
opportunity for public comment as provided in section 408(l)(6) of the 
FFDCA. Although this tolerance expires and is revoked on December 31, 
2009,

[[Page 5626]]

under section 408(l)(5) of the FFDCA, residues of the pesticide not in 
excess of the amounts specified in the tolerance remaining in or on 
bulb onions after that date will be lawful, provided the pesticide is 
applied at a time and in a manner that was lawful under FIFRA, and the 
residues do not exceed a level that was authorized by this time-limited 
tolerance at the time of that application. EPA will take action to 
revoke this time-limited tolerance earlier if any experience with, 
scientific data on, or other relevant information on this pesticide 
indicate that the residues are not safe.
    Because this time-limited tolerance is being approved under 
emergency conditions, EPA has not made any decisions about whether 
avermectin meets EPA's registration requirements for use on bulb onions 
or whether a permanent tolerance for this use would be appropriate. 
Under these circumstances, EPA does not believe that this time-limited 
tolerance serves as a basis for registration of avermectin by a State 
for special local needs under FIFRA section 24(c). Nor does this time-
limited tolerance serve as the basis for any State other than Colorado 
to use this pesticide on this crop under section 18 of FIFRA without 
following all provisions of EPA's regulations implementing FIFRA 
section 18 as identified in 40 CFR part 166. For additional information 
regarding the emergency exemption for avermectin, contact the Agency's 
Registration Division at the address provided under FOR FURTHER 
INFORMATION CONTACT.

IV. Aggregate Risk Assessment and Determination of Safety

    EPA performs a number of analyses to determine the risks from 
aggregate exposure to pesticide residues. For further discussion of the 
regulatory requirements of section 408 of the FFDCA and a complete 
description of the risk assessment process, see http://www.epa.gov/fedrgstr/EPA-PEST/1997/November/Day-26/p30948.htm
.

    Consistent with section 408(b)(2)(D) of the 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 
avermectin and to make a determination on aggregate exposure, 
consistent with section 408(b)(2) of the FFDCA, for a time-limited 
tolerance for combined residues of avermectin B1 and its 
delta-8,9-isomer in or on bulb onions at 0.005 ppm. EPA's assessment of 
the dietary exposures and risks associated with establishing the 
tolerance follows.

A. Toxicological Endpoints

    The dose at which no adverse effects are observed (the NOAEL) from 
the toxicology study identified as appropriate for use in risk 
assessment is used to estimate the toxicological endpoint. However, the 
lowest dose at which adverse effects of concern are identified (the 
LOAEL) is sometimes used for risk assessment if no NOAEL was achieved 
in the toxicology study selected. An uncertainty factor (UF) is applied 
to reflect uncertainties inherent in the extrapolation from laboratory 
animal data to humans and in the variations in sensitivity among 
members of the human population as well as other unknowns. An UF of 100 
is routinely used, 10X to account for interspecies differences and 10X 
for intraspecies differences.
    For dietary risk assessment (other than cancer) the Agency uses the 
UF to calculate an acute or chronic reference dose (acute RfD or 
chronic RfD) where the RfD is equal to the NOAEL divided by the 
appropriate UF (RfD = NOAEL/UF). Where an additional safety factor is 
retained due to concerns unique to the FQPA, this additional factor is 
applied to the RfD by dividing the RfD by such additional factor. The 
acute or chronic Population Adjusted Dose (aPAD or cPAD) is a 
modification of the RfD to accommodate this type of FQPA SF.
    For non-dietary risk assessments (other than cancer) the UF is used 
to determine the level of concern (LOC). For example, when 100 is the 
appropriate UF (10X to account for interspecies differences and 10X for 
intraspecies differences) the LOC is 100. To estimate risk, a ratio of 
the NOAEL to exposures (margin of exposure (MOE) = NOAEL/exposure) is 
calculated and compared to the LOC.
    The linear default risk methodology (Q*) is the primary method 
currently used by the Agency to quantify carcinogenic risk. The Q* 
approach assumes that any amount of exposure will lead to some degree 
of cancer risk. A Q* is calculated and used to estimate risk which 
represents a probability of occurrence of additional cancer cases 
(e.g., risk is expressed as 1 x 10\6\ or one in a million). Under 
certain specific circumstances, MOE calculations will be used for the 
carcinogenic risk assessment. In this non-linear approach, a ``point of 
departure'' is identified below which carcinogenic effects are not 
expected. The point of departure is typically a NOAEL based on an 
endpoint related to cancer effects though it may be a different value 
derived from the dose response curve. To estimate risk, a ratio of the 
point of departure to exposure (MOEcancer = point of 
departure/exposures) is calculated. A summary of the toxicological 
endpoints for avermectin used for human risk assessment can be found in 
a tolerance document published on February 16, 2005, titled 
``Avermectin B1 and its delta-8,9-isomer; Pesticide 
Tolerance'' (70 FR7876; FRL-7695-7).

B. Exposure Assessment

    1. Dietary exposure from food and feed uses. EPA previously 
established tolerances (40 CFR 180.449) for the combined residues of 
avermectin B1 and its delta-8,9-isomer, in or on a variety 
of raw agricultural commodities. Risk assessments were conducted by EPA 
to assess dietary exposures from avermectin in food as follows:
    i. Acute exposure. Acute dietary 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 one day 
or single exposure. The Dietary Exposure Evaluation Model (DEEM\TM\) 
analysis evaluated the individual food consumption as reported by 
respondents in the USDA 1994-1996 and 1998 nationwide Continuing 
Surveys of Food Intake by Individuals (CSFII) and accumulated exposure 
to the chemical for each commodity. The following assumptions were made 
for the acute exposure assessments: A Tier 3, acute probabilistic 
dietary exposure assessment was conducted for all supported food uses 
and drinking water. Acute anticipated residues for many foods were 
derived using market basket survey, new field trial studies and food 
handling establishment request. Estimated concentrations of avermectin 
in drinking water were incorporated directly into the acute assessment.
    ii. Chronic exposure. In conducting the chronic dietary risk 
assessment EPA used the DEEM/FCID which incorporates food consumption 
data as reported by respondents in the USDA 1994-1996 and 1998 
Nationwide CSFII, and accumulated exposure to the chemical for each 
commodity. Percent crop treated and anticipated residues refinements 
were used.
    A Tier 2 chronic dietary exposure assessment was conducted for the 
general U.S. population and various population subgroups. The 
assumptions of the assessment were anticipated residue estimates, 
percent of crop treated (PCT) estimates for most of the commodities, 
and default DEEM processing factors when necessary. Estimated 
concentrations of avermectin in drinking water were incorporated 
directly into the chronic assessment.

[[Page 5627]]

    iii. Cancer. EPA did not perform a cancer aggregate exposure 
assessment because avermectin B1 is classified as a Group E 
chemical and is ``not likely to be carcinogenic to humans.''
    iv. Anticipated residue and PCT information. Section 408(b)(2)(E) 
of the 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 chemicals that have been measured in food. 
If EPA relies on such information, EPA must pursuant to section 
408(f)(1) require 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. Following the initial 
data submission, EPA is authorized to require similar data on a time 
frame it deems appropriate. For the present action, EPA will issue such 
Data Call-Ins for information relating to anticipated residues as are 
required by FFDCA section 408(b)(2)(E) and authorized under FFDCA 
section 408(f)(1). Such data call-ins will be required to be submitted 
no later than 5 years from the date of issuance of this tolerance.
    Section 408(b)(2)(F) of the FFDCA states that the Agency may use 
data on the actual percent of food treated for assessing chronic 
dietary risk only if the Agency can make the following findings: 
Condition 1, that 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 such pesticide residue; Condition 2, that the exposure estimate 
does not underestimate exposure for any significant subpopulation 
group; and Condition 3, if 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 section 408(b)(2)(F) of the FFDCA, EPA may require registrants to 
submit data on PCT.
    The Agency used PCT information as follows: Almonds 21%; avocado 
20%; balsam pear 1%; cantaloupe 7%; casabas 1%; chayote fruit 1%; 
Chinese waxgourd 1%; cotton 3%; cress (garden, upland) 1%; cucumber 1%; 
grape 6%; hops 82%; honeydew melon 1%; plum 1%; pumpkin 1%; squash 1%; 
strawberry 44%; walnut 2%; watermelon 7%.
    The Agency believes that the three conditions listed above have 
been met. With respect to Condition 1, PCT estimates are derived from 
Federal and private market survey data, which are reliable and have a 
valid basis. EPA uses a weighted average PCT for chronic dietary 
exposure estimates. This weighted average PCT figure is derived by 
averaging State-level data for a period of up to 10 years, and 
weighting for the more robust and recent data. A weighted average of 
the PCT reasonably represents a person's dietary exposure over a 
lifetime, and is unlikely to underestimate exposure to an individual 
because of the fact that pesticide use patterns (both regionally and 
nationally) tend to change continuously over time, such that an 
individual is unlikely to be exposed to more than the average PCT over 
a lifetime. For acute dietary exposure estimates, EPA uses an estimated 
maximum PCT. The exposure estimates resulting from this approach 
reasonably represent the highest levels to which an individual could be 
exposed, and are unlikely to underestimate an individual's acute 
dietary exposure. The Agency is reasonably certain that the percentage 
of the food treated is not likely to be an underestimation. As to 
Conditions 2 and 3, 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 
information on the regional consumption of food to which avermectin may 
be applied in a particular area.
    2. Dietary exposure from drinking water. The Agency lacks 
sufficient monitoring exposure data to complete a comprehensive dietary 
exposure analysis and risk assessment for avermectin in drinking water. 
Because the Agency does not have comprehensive monitoring data, 
drinking water concentration estimates are made by reliance on 
simulation or modeling taking into account data on the physical 
characteristics of 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.

    Tier II screening models PRZM (Pesticide Root Zone Model) and EXAMS 
(Exposure Analysis Modeling System) were used to determine estimated 
surface water concentrations of avermectin based on the modeled 
scenario of one seed treatment to cucumbers followed by 3 aerial 
applications at a 7-day interval in Florida. This use of abamectin 
represents the worst case potential contribution of abamectin to 
drinking water when considering currently registered uses, including 
this one.
    The full PRZM/EXAMS distribution was used for the acute dietary 
assessment, and the 1-in-10 year annual mean concentration of 0.244 ppm 
was used for chronic dietary estimates. Modeled estimates of drinking 
water concentrations were directly entered into the dietary exposure 
model.
    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).
    Avermectin is currently registered for use on the following 
residential non-dietary sites: Residential lawn application for fire 
ant control and residential indoor crack and crevice application for 
cockroaches and ants. These registered residential uses may result in 
short-term to intermediate-term exposures; however, based on current 
use patterns, long-term exposure (6 or more months of continuous 
exposure) to avermectin is not expected. Adults may be exposed through 
handling the pesticide and both adults and children may be exposed 
through contact with treated areas following application. Accordingly, 
handler and post-application exposures were assessed for two major 
categories of residential avermectin use which are considered to 
represent the reasonable high-end residential exposure potential: 
Granular baits used to treat lawns, and indoor crack and crevice dust 
products.
    4. Cumulative effects from substances with a common mechanism of 
toxicity. Section 408(b)(2)(D)(v) of the 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.''
    Unlike other pesticides for which EPA has followed a cumulative 
risk approach based on a common mechanism of

[[Page 5628]]

toxicity, EPA has not made a common mechanism of toxicity finding as to 
avermectin and any other substances and avermectin does not appear to 
produce a toxic metabolite produced by other substances. For the 
purposes of this tolerance action, therefore, EPA has not assumed that 
avermectin has 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 the policy statements released by EPA's 
Office of Pesticide Programs concerning common mechanism determinations 
and procedures for cumulating effects from substances found to have a 
common mechanism on EPA's website at http://www.epa.gov/pesticides/cumulative/
.

C. Safety Factor for Infants and Children

     In general. Section 408 of the FFDCA provides that EPA shall apply 
an additional tenfold 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 that a different margin of safety will be safe 
for infants and children. Margins of safety are incorporated into EPA 
risk assessments either directly through use of a MOE analysis or 
through using uncertainty (safety) factors in calculating a dose level 
that poses no appreciable risk to humans.
    For avermectin B1 EPA retained the default 10X factor 
based on the following combination of factors:
     There is residual uncertainty due to a data gap for a 
developmental neurotoxicity study (DNT), as well as data gaps for acute 
and subchronic neurotoxicity studies. These studies are required 
because avermectin B1 has been shown to be neurotoxic, with 
multiple neurotoxic clinical signs (including head and body tremors and 
limb splay) seen in multiple studies with multiple species.
     For several species, the dose-response curve appears to be 
steep.
     Severe effects were seen at the LOAELs in several studies 
(death, neurotoxicity, and developmental toxicity). Although increased 
susceptibility of the young was observed in several studies, the degree 
of concern with that susceptibility was judged to be low. Increased 
susceptibility (qualitative and/or quantitative) was seen in prenatal 
developmental toxicity studies in CD-1 mice and rabbits following in 
utero exposure to avermectin B1. There was also an increase 
in quantitative and qualitative susceptibility in the rat reproductive 
toxicity study. The concern for susceptibility seen in the 
developmental study with rabbits and in the reproductive toxicity study 
in the rat is low because the lowest NOAEL obtained (0.12 milligrams/
kilogram/day (mg/kg/day)) was used as the basis for the cRfD and other 
non-dietary risk assessment scenarios, which is protective of all of 
the developmental/offspring effects seen in those studies. Similarly, 
the concern for susceptibility seen at the LOAEL in the CD-1 mouse 
developmental toxicity study is low, since the NOAEL in the rat 
reproductive toxicity study is lower than the dose at which effects 
were seen in the CD-1 mouse.

D. Aggregate Risks and Determination of Safety.

    The Agency currently has two ways to estimate total aggregate 
exposure to a pesticide from food, drinking water, and residential 
uses. First, a screening assessment can be used, in which the Agency 
calculates drinking water levels of comparison (DWLOCs) which are used 
as a point of comparison against estimated drinking water 
concentrations (EDWCs). The DWLOC values are not regulatory standards 
for drinking water, but are theoretical upper limits on a pesticide's 
concentration in drinking water in light of total aggregate exposure to 
a pesticide in food and residential uses. More information on the use 
of DWLOCs in dietary aggregate risk assessments can be found at http://www.epa.gov/oppfead1/trac/science/screeningsop.pdf
.

    More recently the Agency has used another approach to estimate 
aggregate exposure through food, residential and drinking water 
pathways. In this approach, modeled surface and ground water EDWCs are 
directly incorporated into the dietary exposure analysis, along with 
food. This provides a more realistic estimate of exposure because 
actual body weights and water consumption from the CSFII are used. The 
combined food and water exposures are then added to estimated exposure 
from residential sources to calculate aggregate risks. The resulting 
exposure and risk estimates are still considered to be high end, due to 
the assumptions used in developing drinking water modeling inputs. The 
risk assessment for avermectin used in this tolerance document uses 
this approach of incorporating water exposure directly into the dietary 
exposure analysis.
    1. Acute risk. Using the exposure assumptions discussed in this 
unit for acute exposure, the acute dietary exposure from food and water 
to avermectin will occupy 42% of the aPAD for the U.S. population, 7% 
of the aPAD for females 13 years and older, 89% of the aPAD for all 
infants less than 1-year old and 71% of the aPAD for children 1-2 years 
old.
    2. Chronic risk. Using the exposure assumptions described in this 
unit for chronic exposure, EPA has concluded that exposure to 
avermectin from food will utilize 9% of the cPAD for the U.S. 
population, 21% of the cPAD for all infants less than 1 year old and 
21% of the cPAD for children 1-2 years old. Based on the use pattern, 
chronic residential exposure to residues of avermectin is not 
expected..
    3. Short-term and intermediate-term risk. Short-term and 
intermediate-term aggregate exposure takes into account residential 
exposure plus chronic exposure to food and water (considered to be a 
background exposure level).
    Avermectin is currently registered for use(s) that could result in 
short-term and intermediate-term residential exposure and the Agency 
has determined that it is appropriate to aggregate chronic food and 
water and short-term and intermediate-term exposures for avermectin.
    Using the exposure assumptions described in this unit for short-
term and intermediate-term exposures, EPA has concluded that food, 
water and residential exposures aggregated result in the following 
aggregate MOEs: 2,900 for the U.S. population, and 1,700 for children 
1-2 years old. These aggregate MOEs do not exceed the Agency's level of 
concern of 1,000 for aggregate exposure to food, water and residential 
uses.
    4. Aggregate cancer risk for U.S. population. EPA has not performed 
a cancer aggregate risk assessment because avermectin has been 
classified as a Group E chemical by the Agency and is ``not likely to 
be carcinogenic to humans.''
    5. Determination of safety. Based on these risk assessments which 
indicate that all avermectin risks are below the Agency's levels of 
concern, EPA concludes that there is a reasonable certainty that no 
harm will result to the general population, and to infants and children 
from aggregate exposure to avermectin residues.

V. Other Considerations

A. Analytical Enforcement Methodology

    Adequate enforcement methodology is available to enforce the 
tolerance expression. The method may be requested from: Chief, 
Analytical Chemistry Branch, Environmental Science Center, 701 Mapes 
Rd., Ft.

[[Page 5629]]

Meade, MD 20755-5350; telephone number: (410) 305-2905; e-mail address: 
residuemethods@epa.gov.

B. International Residue Limits

    There are no CODEX residue limits for residues of avermectin on 
onions, therefore, harmonization is not an issue.

VI. Conclusion

    Therefore, the time-limited tolerance is established for combined 
residues of the insecticide 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 bulb onions at 0.005 ppm. The time-limited 
tolerance expires and is revoked on December 31, 2009.

VII. Statutory and Executive Order Reviews

    This final rule establishes a time-limited tolerance under section 
408 of the FFDCA. 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 rule has been exempted from review under Executive 
Order 12866 due to its lack of significance, this rule is not subject 
to Executive Order 13211, Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355, 
May 22, 2001). 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., or impose any enforceable duty or 
contain any unfunded mandate as described under Title II of the 
Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 104-4). 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); 
or OMB review or any Agency action under Executive Order 13045, 
entitled Protection of Children from Environmental Health Risks and 
Safety Risks (62 FR 19885, April 23, 1997). 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 Transfer and Advancement Act of 1995 (NTTAA), 
Public Law 104-113, section 12(d) (15 U.S.C. 272 note). Since 
tolerances and exemptions that are established on the basis of a FIFRA 
section 18 exemption under section 408 of the 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. In addition, the Agency has 
determined that this action will not have a substantial direct effect 
on States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government, as specified in Executive Order 13132, 
entitled Federalism (64 FR 43255, August 10, 1999). Executive Order 
13132 requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.'' This final 
rule directly regulates growers, food processors, food handlers, and 
food retailers, not States. This action does not alter the 
relationships or distribution of power and responsibilities established 
by Congress in the preemption provisions of section 408(n)(4) of the 
FFDCA. For these same reasons, the Agency has determined that this rule 
does not have any ``tribal implications'' as described in Executive 
Order 13175, entitled Consultation and Coordination with Indian Tribal 
Governments (65 FR 67249, November 6, 2000). Executive Order 13175, 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' ``Policies that have tribal 
implications'' is defined in the Executive Order to include regulations 
that have ``substantial direct effects on one or more Indian tribes, on 
the relationship between the Federal Government and the Indian tribes, 
or on the distribution of power and responsibilities between the 
Federal Government and Indian tribes.'' This rule will not have 
substantial direct effects on tribal governments, on the relationship 
between the Federal Government and Indian tribes, or on the 
distribution of power and responsibilities between the Federal 
Government and Indian tribes, as specified in Executive Order 13175. 
Thus, Executive Order 13175 does not apply to this rule.

VIII. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
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: January 24, 2007.
Lois Rossi,
Director, Registration Division, Office of Pesticide Programs.

0
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 by adding text after the heading in 
paragraph (b) to read as follows:

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

* * * * *
    (b) Section 18 emergency exemptions. Time-limited tolerances are 
established for the residues of avermectin B1 and it delta-
8,9-isomer, in connection with use of the pesticide under section 18 
emergency exemptions granted by EPA. The tolerances are specified in 
the following table. The tolerances will expire on the dates specified 
in the table.

[[Page 5630]]

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          Commodity                     Parts per million                    Expiration/revocation date
----------------------------------------------------------------------------------------------------------------
Onion, bulb                                                 0.005                                       12/31/09
----------------------------------------------------------------------------------------------------------------

* * * * *
[FR Doc. E7-2003 Filed 2-6-07; 8:45 am]

BILLING CODE 6560-50-S