[Federal Register Volume 62, Number 53 (Wednesday, March 19, 1997)]
[Rules and Regulations]
[Pages 12953-12959]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-6654]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300460; FRL-5594-2]
RIN 2070-AB78
Imidacloprid; 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 pesticide imidacloprid in or on the raw
agricultural commodity crop group, cucurbits (Crop Group 9 cucumbers,
melons, and squash) in connection with EPA's granting of emergency
exemptions under section 18 of the Federal Insecticide, Fungicide, and
Rodenticide Act authorizing use of imidacloprid on cucurbits in Texas
and California. This regulation establishes maximum permissible levels
for residues of imidacloprid in these foods. This tolerance will expire
on March 31, 1998.
DATES: This regulation becomes effective March 19, 1997. The entry in
the table expires on March 31, 1998. Objections and requests for
hearings must be received by EPA on or before May 19, 1997.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300460], must be submitted to: Hearing
Clerk (1900), Environmental Protection Agency, Rm. M3708, 401 M St.,
SW., Washington, DC 20460. Fees accompanying objections and hearing
requests shall be labeled ``Tolerance Petition Fees'' and forwarded to:
EPA Headquarters Accounting Operations Branch, OPP (Tolerance Fees),
P.O. Box 360277M, Pittsburgh, PA 15251. A copy of any objections and
hearing requests filed with the Hearing Clerk identified by the docket
control number, [OPP-300460], must also be submitted to: Public
Response and Program Resources Branch, Field Operations Division
(7506C), Office of Pesticide Programs, Environmental Protection Agency,
401 M St., SW., Washington, DC 20460. In person, bring a copy of
objections and hearing requests to Rm. 1132, CM #2, 1921 Jefferson
Davis Highway., Arlington, VA.
A copy of objections and hearing requests filed with the Hearing
Clerk may also be submitted electronically by sending electronic mail
(e-mail) to: opp-docket@epamail.epa.gov. Such copies of objections and
hearing requests must be submitted as an ASCII file avoiding the use of
special characters and any form of encryption. Copies of objections and
hearing requests will also be accepted on disks in WordPerfect 5.1 file
format or ASCII file format. All copies of objections and hearing
requests in electronic form must be identified by the docket control
number [OPP-300460]. No Confidential Business Information (CBI) should
be submitted through e-mail. Electronic copies of objections and
hearing requests on this rule may be filed online at many Federal
Depository Libraries.
FOR FURTHER INFORMATION CONTACT: By mail: Andrea Beard, Registration
Division (7505W), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St., SW., Washington, DC 20460. Office
location, telephone number, and e-mail: Sixth Floor, Crystal Station
#1, 2800 Jefferson Davis Highway, Arlington, VA 22202. (703) 308-8791,
e-mail: beard.andrea@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: EPA, pursuant to section 408(e) and (l)(6)
of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 346a(e)
and (l)(6), is establishing tolerances for residues of the pesticide
imidacloprid (1-[(6-chloro-3-pyridinyl)methyl]-N-nitro-2-
imidazolidinimine), in or on cucurbits, at 0.2 part per million (ppm).
This tolerance will expire and be revoked automatically without further
action by EPA on March 31, 1998.
[[Page 12954]]
I. Background and Statutory Authority
The Food Quality Protection Act of 1996 (FQPA) (Pub. L. 104-170)
was signed into law August 3, 1996. FQPA amends both the Federal Food,
Drug, and Cosmetic Act (FFDCA), 21 U.S.C. 301 et seq., and the FIFRA, 7
U.S.C. 136 et seq. The FQPA amendments went into effect immediately.
Among other things, FQPA amends FFDCA to bring all EPA pesticide
tolerance-setting activities under a new section 408 with a new safety
standard and new procedures. These activities are described below and
discussed in greater detail in the final rule establishing the time-
limited tolerance associated with the emergency exemption for use of
propiconazole on sorghum (61 CFR 58135, November 13, 1996)(FRL-5572-9).
New section 408(b)(2)(A)(i) 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) 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, but does not include
occupational exposure. Section 408(b)(2)(C) 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 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 FQPA. EPA has established regulations governing such
emergency exemptions in 40 CFR part 166.
Section 408(l)(6) 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. Section 408(l)(6) also requires EPA to promulgate regulations
by August 3, 1997, governing the establishment of tolerances and
exemptions under section 408(l)(6) and requires that the regulations be
consistent with section 408(b)(2) and (c)(2) and FIFRA section 18.
Section 408(l)(6) allows EPA to establish tolerances or exemptions
from the requirement for a tolerance, in connection with EPA's granting
of FIFRA section 18 emergency exemptions, without providing notice or a
period for public comment. Thus, consistent with the need to act
expeditiously on requests for emergency exemptions under FIFRA, EPA can
establish such tolerances or exemptions under the authority of section
408(e) and (l)(6) without notice and comment rulemaking.
In establishing section 18-related tolerances and exemptions during
this interim period before EPA issues the section 408(l)(6) procedural
regulation and before EPA makes its broad policy decisions concerning
the interpretation and implementation of the new section 408, EPA does
not intend to set precedents for the application of section 408 and the
new safety standard to other tolerances and exemptions. Rather, these
early section 18 tolerance and exemption decisions will be made on a
case-by-case basis and will not bind EPA as it proceeds with further
rulemaking and policy development. EPA intends to act on section 18-
related tolerances and exemptions that clearly qualify under the new
law.
II. Emergency Exemption for Imidacloprid on Cucurbits and FFDCA
Tolerances
The Texas Department of Agriculture and the California Department
of Pesticide Regulation availed themselves of the authority to declare
the existence of a crisis situation within their states, on January 27,
and February 5, 1997, respectively, thereby authorizing use under FIFRA
section 18 of imidacloprid on cucurbits to control white flies. The
States of Texas and California have also requested specific exemptions
for this use of imidacloprid. Texas and California stated that an
emergency situation was present due to this recently introduced pest,
its devastating effects on the cucurbit crop, and its resistance to
registered alternatives. Texas and California state that this pest can
have devastating effects on growers' production and revenue. After
having reviewed their submission, EPA concurs that an emergency
condition exists.
As part of its assessment of these crisis declarations, EPA
assessed the potential risks presented by residues of imidacloprid in
or on cucurbits. In doing so, EPA considered the new safety standard in
FFDCA section 408(b)(2), and EPA decided to grant the section 18
exemptions only after concluding that the necessary tolerance under
FFDCA section 408(l)(6) would clearly be consistent with the new safety
standard and with FIFRA section 18. This tolerance for imidacloprid
will permit the marketing of cucurbits treated in accordance with the
provisions of the section 18 emergency exemptions. Consistent with the
need to move quickly on the emergency exemptions and to ensure that the
resulting food is safe and lawful, EPA is issuing this tolerance
without notice and opportunity for public comment under section 408(e)
as provided for in section 408(l)(6). Although this tolerance will
expire and be revoked automatically without further action by EPA on
March 31, 1998, under FFDCA section 408(l)(5), residues of imidacloprid
not in excess of the amount specified in the tolerance remaining in or
on cucurbits after that date will not be unlawful, provided the
pesticide is applied during the term of, and in accordance with all the
conditions of, the emergency exemptions. EPA will take action to revoke
this tolerance earlier if any experience with, scientific data on, or
other relevant information on this pesticide indicate that the residues
are not safe.
EPA has not made any decisions about whether imidacloprid meets the
requirements for registration under FIFRA section 3 for use on
cucurbits, or whether a permanent tolerance for imidacloprid for
cucurbits would be appropriate. This action by EPA does not serve as a
basis for registration of imidacloprid by a State for special local
needs under FIFRA section 24(c). Nor does this action serve as the
basis for any State other than Texas and California to use this product
on this crop under section 18 of FIFRA without following all provisions
of section 18 as identified in 40 CFR part 166. For additional
information regarding the emergency exemptions for imidacloprid,
contact the Agency's Registration Division at the address provided
above.
III. Risk Assessment and Statutory Findings
EPA performs a number of analyses to determine the risks from
aggregate exposure to pesticide residues. First, EPA determines the
toxicity of pesticides based primarily on toxicological studies using
laboratory animals. These studies address many adverse health effects,
including (but not limited to) reproductive effects, developmental
toxicity, toxicity to the nervous system, and carcinogenicity. For many
of these studies, a dose-response relationship can be determined, which
provides a dose that
[[Page 12955]]
causes adverse effects (threshold effects) and doses causing no
observed effects (the ``no-observed effect level'' or ``NOEL'').
Once a study has been evaluated and the observed effects have been
determined to be threshold effects, EPA generally divides the NOEL from
the study with the lowest NOEL by an uncertainty factor (usually 100 or
more) to determine the Reference Dose (RfD). The RfD is a level at or
below which daily aggregate exposure over a lifetime will not pose
appreciable risks to human health. An uncertainty factor (sometimes
called a ``safety factor'') of 100 is commonly used since it is assumed
that people may be up to 10 times more sensitive to pesticides than the
test animals, and that one person or subgroup of the population (such
as infants and children) could be up to 10 times more sensitive to a
pesticide than another. In addition, EPA assesses the potential risks
to infants and children based on the weight of the evidence of the
toxicology studies and determines whether an additional uncertainty
factor is warranted. Thus, an aggregate daily exposure to a pesticide
residue at or below the RfD (expressed as 100 percent or less of the
RfD) is generally considered by EPA to pose a reasonable certainty of
no harm.
Lifetime feeding studies in two species of laboratory animals are
conducted to screen pesticides for cancer effects. When evidence of
increased cancer is noted in these studies, the Agency conducts a
weight-of-the-evidence review of all relevant toxicological data
including short-term and mutagenicity studies and structure-activity
relationships. Once a pesticide has been classified as a potential
human carcinogen, different types of risk assessments (e.g., linear
low-dose extrapolations or margin of exposure calculation based on the
appropriate NOEL) will be carried out based on the nature of the
carcinogenic response and the Agency's knowledge of its mode of action.
In examining aggregate exposure, FFDCA section 408 requires that
EPA take into account available and reliable information concerning
exposure from the pesticide residue in the food in question, residues
in other foods for which there are tolerances, and other non-
occupational exposures, such as where residues leach into groundwater
or surface water that is consumed as drinking water. Dietary exposure
to residues of a pesticide in a food commodity are estimated by
multiplying the average daily consumption of the food forms of that
commodity by the tolerance level or the anticipated pesticide residue
level. The Theoretical Maximum Residue Contribution (TMRC) is an
estimate of the level of residues consumed daily if each food item
contained pesticide residues equal to the tolerance. The TMRC is a
``worst case'' estimate since it is based on the assumptions that food
contains pesticide residues at the tolerance level and that 100 percent
of the crop is treated by pesticides that have established tolerances.
If the TMRC exceeds the RfD or poses a lifetime cancer risk that is
greater than approximately one in a million, EPA attempts to derive a
more accurate exposure estimate for the pesticide by evaluating
additional types of information (anticipated residue data and/or
percent of crop treated data) which show, generally, that pesticide
residues in most foods when they are eaten are well below established
tolerances.
IV. Aggregate Risk Assessments, Cumulative Risk Discussion, and
Determination of Safety
Consistent with section 408(b)(2)(D), EPA has reviewed the
available scientific data and other relevant information in support of
this action. Imidacloprid is registered by EPA for use on turf, as a
termiticide, and for flea control on pets. At this time EPA is not in
possession of a registration application for imidacloprid on cucurbits.
However, based on information submitted to the Agency, EPA has
sufficient data to assess the hazards of imidacloprid and to make a
determination on aggregate exposure, consistent with section 408(b)(2),
for the time-limited tolerance for residues of imidacloprid on
cucurbits at 0.2 ppm. EPA's assessment of the dietary exposures and
risks associated with establishing this tolerance follows.
A. Toxicological Profile
1. Chronic toxicity. Based on the available chronic toxicity data,
the EPA's Office of Pesticide Programs (OPP) has established the RfD
for imidacloprid at 0.057 milligrams/kilogram/day (mg/kg/day). The RfD
for imidacloprid is based on a 2-year feeding study in rats with a NOEL
of 5.7 mg/kg/day and an uncertainty factor of 100. An increase in
thyroid lesions in males was observed at the Lowest Effect Level (LEL)
at 16.9 mg/kg/day.
2. Acute toxicity. Based on the available acute toxicity data, OPP
has determined that the NOEL of 24 mg/kg/day from the developmental
toxicity study in rabbits should be used to assess risk from acute
toxicity. Maternal effects observed at the LEL of 72 mg/kg/day included
decreased body weight and increased resorptions and abortions. Fetal
effects observed at the LEL of 72 mg/kg/day included an increase in
skeletal abnormalities. The population subgroup of concern for this
risk assessment is females 13+ years and older. This subgroup takes
into account both maternal and fetal effects.
3. Short- and intermediate-term toxicity. OPP has determined that
available data do not demonstrate that imidacloprid has dermal or
inhalation toxicity potential. Therefore, short-term or intermediate-
term dermal and inhalation risk assessments, for occupational and
residential exposure scenarios, are not required.
4. Carcinogenicity. Using its Guidelines for Carcinogen Risk
Assessment published September 24, 1986 (51 FR 33992), EPA has
classified imidacloprid as a ``Group E'' chemical (no evidence of
carcinogenicity for humans) based on the results of carcinogenicity
studies in two species. The doses tested are adequate for identifying a
cancer risk. Thus, a cancer risk assessment would not be appropriate.
B. Aggregate Exposure
Tolerances have been established (40 CFR 180.472) for the combined
residues of imidacloprid (1-[(6-chloro-3-pyridinyl)methyl]-N-nitro-2-
imidazolidinimine) and its metabolites containing 6-chloropyridinyl
moiety expressed in or on certain raw agricultural commodities ranging
from 0.02 ppm in eggs to 3.5 ppm in Brassica vegetable crop group
(cabbage, chinese cabbage, and Kale) and head and leaf lettuce. There
are no livestock feed items associated with these section 18 requests,
so no additional livestock dietary burden will result from this section
18 registration. Therefore, existing meat/milk/poultry tolerances are
adequate.
In conducting this exposure assessment, EPA has made very
conservative assumptions -- 100% of cucurbits and all other commodities
having imidacloprid tolerances will contain imidacloprid tolerance
residues and those residues would be at the level of the tolerance --
which result in an overestimate of human dietary exposure. Thus, in
making a safety determination for this tolerance, EPA is taking into
account this conservative exposure assessment.
1. Chronic exposure. Given the emergency nature of this request for
the use of imidacloprid and the resulting need for a timely analysis
and risk assessment, EPA has utilized the TMRC to estimate chronic
dietary exposure
[[Page 12956]]
from the tolerances for imidacloprid on cucurbits at 0.2 ppm. The TMRC
is obtained by multiplying the tolerance level residue for cucurbits by
the average consumption data, which estimate the amount of cucurbits
eaten by various population subgroups. This calculation is performed as
well for every food having existing imidacloprid tolerances. The risk
assessment is therefore considered to be overestimated. The Agency has
extensive experience refining chronic dietary risk assessments for a
broad range of pesticide chemicals. It is OPP's experience that when
the chronic dietary risk assessment is refined using anticipated
residue contribution (ARC) estimates derived from anticipated residue
levels and percent crop treated data, the percent of the RfD occupied
by the ARC is generally in the range of an order of magnitude lower
than the percent of the RfD occupied by the unrefined TMRC. A similar
decrease in estimated exposure to imidacloprid is expected once more
refined data is received based on ARCs for imidacloprid on some crops.
In examining aggregate exposure, FQPA directs EPA to consider
available information concerning exposures from the pesticide residue
in food and all other non-occupational exposures. The primary non-food
sources of exposure the Agency looks at include drinking water (whether
from groundwater or surface water), and exposure through pesticide use
in gardens, lawns, or buildings (residential and other indoor uses).
Based on the available studies used in EPA's assessment of
environmental risk, imidacloprid is persistent and could potentially
leach into groundwater, and run off to surface water under certain
environmental conditions. There is no established Maximum Concentration
Level (MCL) for residues of imidacloprid in drinking water. No drinking
water health advisories have been issued for imidacloprid. The
``Pesticides in Groundwater Database'' (EPA 734-12-92-001, September
1992) has no information concerning imidacloprid.
Because the Agency lacks sufficient water-related exposure data to
complete a comprehensive drinking water risk assessment for many
pesticides, EPA has commenced and nearly completed a process to
identify a reasonable yet conservative bounding figure for the
potential contribution of water-related exposure to the aggregate risk
posed by a pesticide. In developing the bounding figure, EPA estimated
residue levels in water for a number of specific pesticides using
various data sources. The Agency then applied the estimated residue
levels, in conjunction with appropriate toxicological endpoints (RfD's
or acute dietary NOEL's) and assumptions about body weight and
consumption, to calculate, for each pesticide, the increment of
aggregate risk contributed by consumption of contaminated water. While
EPA has not yet pinpointed the appropriate bounding figure for
consumption of contaminated water, the ranges the Agency is continuing
to examine are all below the level that would cause imidacloprid to
exceed the RfD if the tolerance being considered in this document were
granted. The Agency has therefore concluded that the potential
exposures associated with imidacloprid in water, even at the higher
levels the Agency is considering as a conservative upper bound, would
not prevent the Agency from determining that there is a reasonable
certainty of no harm if the tolerance is granted.
2. Acute exposure. EPA has not estimated non-occupational exposures
other than dietary for imidacloprid. Acceptable, reliable data are not
currently available with which to assess acute risk. Imidacloprid is
registered for turf pest control. While dietary and residential
scenarios could possibly occur in a single day, imidacloprid would
rarely be present on both the food eaten and the lawn on that single
day. Even assuming this were the case, it is yet more unlikely that
residues would be present at tolerance level on all food eaten that day
for which imidacloprid tolerances exist, as is assumed in the acute
dietary risk analysis, and on the lawn that same day. Because the acute
dietary exposure estimate assumes tolerance level residues and 100%
crop treated for all crops evaluated, it is a large over-estimate of
exposure and it is considered to be protective of any acute exposure
scenario.
C. Cumulative Exposure to Substances with Common Mechanism of Toxicity
Section 408(b)(2)(D)(v) 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.'' The Agency believes that ``available
information'' in this context might include not only toxicity,
chemistry, and exposure data, but also scientific policies and
methodologies for understanding common mechanisms of toxicity and
conducting cumulative risk assessments. For most pesticides, although
the Agency has some information in its files that may turn out to be
helpful in eventually determining whether a pesticide shares a common
mechanism of toxicity with any other substances, EPA does not at this
time have the methodologies to resolve the complex scientific issues
concerning common mechanism of toxicity in a meaningful way. EPA has
begun a pilot process to study this issue further through the
examination of particular classes of pesticides. The Agency hopes that
the results of this pilot process will increase the Agency's scientific
understanding of this question such that EPA will be able to develop
and apply scientific principles for better determining which chemicals
have a common mechanism of toxicity and evaluating the cumulative
effects of such chemicals. The Agency anticipates, however, that even
as its understanding of the science of common mechanisms increases,
decisions on specific classes of chemicals will be heavily dependent on
chemical-specific data, much of which may not be presently available.
Although at present the Agency does not know how to apply the
information in its files concerning common mechanism issues to most
risk assessments, there are pesticides as to which the common mechanism
issues can be resolved. These pesticides include pesticides that are
toxicologically dissimilar to existing chemical substances (in which
case the Agency can conclude that it is unlikely that a pesticide
shares a common mechanism of activity with other substances) and
pesticides that produce a common toxic metabolite (in which case common
mechanism of activity will be assumed).
EPA does not have, at this time, available data to determine
whether imidacloprid has a common mechanism of toxicity with other
substances or how to include this pesticide in a cumulative risk
assessment. Unlike other pesticides for which EPA has followed a
cumulative risk approach based on a common mechanism of toxicity,
imidacloprid 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 imidacloprid has a common mechanism of
toxicity with other substances.
D. Determination of Safety for U.S. Population
1. Chronic risk. Using the conservative exposure assumptions
described above, and taking into account the completeness and
reliability of the toxicity data, EPA has concluded
[[Page 12957]]
that aggregate dietary exposure to imidacloprid will utilize 16% of the
RfD for the U.S. population. EPA generally has no concern for exposures
below 100 percent of the RfD because the RfD represents the level at or
below which daily aggregate dietary exposure over a lifetime will not
pose appreciable risks to human health. Despite the potential for
exposure to imidacloprid in drinking water, EPA does not expect the
aggregate exposure to exceed 100% of the RfD. EPA concludes that there
is a reasonable certainty that no harm will result from aggregate
exposure to imidacloprid residues.
2. Acute risk. For the population subgroup of concern, females 13+
and older (accounts for both maternal and fetal exposure), the
calculated Margin of Exposure (MOE) value is 480. This MOE does not
exceed the Agency's level of concern for acute dietary exposure.
E. Determination of Safety for Infants and Children
In assessing the potential for additional sensitivity of infants
and children to residues of imidacloprid, EPA considered data from
developmental toxicity studies in the rat and rabbit and a 2-generation
reproduction study in the rat. The developmental toxicity studies are
designed to evaluate adverse effects on the developing organism
resulting from pesticide exposure during prenatal development to one or
both parents. Reproduction studies provide information relating to
effects from exposure to the pesticide on the reproductive capability
of mating animals and data on systemic toxicity.
In the rat developmental study, the maternal (systemic) NOEL was 30
mg/kg/day, based on decreased weight gain at the LOEL of 100 mg/kg/day.
The developmental (fetal) NOEL was 30 mg/kg/day based on increased wavy
ribs at the LOEL of 100 mg/kg/day. In the rabbit developmental study,
the maternal (systemic) NOEL was 24 mg/kg/day, based on decreased body
weight, increased resorptions and abortions, and death at the LOEL of
72 mg/kg/day. The developmental (fetal) NOEL was 24 mg/kg/day, based on
decreased body weight and increased skeletal anomalies at the LOEL of
72 mg/kg/day.
In the rat developmental study, the developmental (fetus) and
maternal (mother) NOELs occur at the same dose level, 24 mg/kg/day. The
same response is seen in the rabbit developmental study with the
developmental (fetus) and maternal (mother) NOELs occurring at the same
dose level of 30 mg/kg/day. This suggests that there are no special
prenatal sensitivities for unborn children in the absence of maternal
toxicity. However, a detailed analysis of the developmental studies
indicates that the skeletal findings (wavy ribs and other anomalies) in
both the rat and rabbit fetuses are severe malformations which occurred
in the presence of slight toxicity (decreases of body weight) in the
maternal animals. Additionally, in rabbits, there were resorptions and
abortions which can be attributed to acute maternal exposure. This
information has been interpreted by the Toxicology Endpoint Selection
Committee (TESC) as indicating a potential acute dietary risk for pre-
natally exposed infants.
In the rat reproduction study, the maternal (systemic) NOEL was 55
mg/kg/day (the highest dose tested). The reproductive/developmental
NOEL (effect on the pup) was 8 mg/kg/day, based on decreased pup body
weight during lactation in both generations at the LOEL of 19 mg/kg/
day.
In the 2-generation rat reproduction study, the maternal NOEL is 55
mg/kg/day and the NOEL for decreased pup body weight during lactation
is 8 mg/kg/day with the LOEL at 19 mg/kg/day. This study shows that
adverse postnatal development of pups occurs at levels (19 mg/kg/day)
which are lower than the NOEL for the parental animals (55 mg/kg/day).
Therefore, the pups are more sensitive to the effects of imidacloprid
than parental animals. The pup NOEL of 8 mg/kg/day in the reproduction
study is 1.4 times greater than the NOEL of 5.7 from the 2-year rat
feeding study which was the basis of the RfD. The TMRC value for the
most highly exposed infants and children subgroup (children 1 to 6
years old) occupies 31.0% of the RfD.
1. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that the percent of the RfD that
will be utilized by aggregate exposure to residues of imidacloprid
ranges from 12 percent for nursing infants, up to 32 percent for
children 1 to 6 years old. Therefore, taking into account the
completeness and reliability of the toxicity data and the conservative
exposure assessment, EPA concludes that there is a reasonable certainty
that no harm will result to infants and children from aggregate
exposure to imidacloprid residues.
2. Acute risk. At present, the acute dietary MOE for females 13+
years old (accounts for both maternal and fetal exposure) is 480. This
MOE calculation was based on the developmental NOEL in rabbits of 24
mg/kg/day. Maternal effects observed at the LEL of 72 mg/kg/day
included decreased body weight and increased resorptions and abortions.
Fetal effects observed at the LEL of 72 mg/kg/day included an increase
in skeletal abnormalities. This risk assessment also assumed 100% crop
treated with tolerance level residues on all treated crops consumed,
resulting in a significant over-estimate of dietary exposure. The large
acute dietary MOE calculated for females 13+ years old provides
assurance that there is a reasonable certainty of no harm for both
females 13+ years and the pre-natal development of infants.
FFDCA section 408 provides that EPA shall apply an additional
tenfold margin of exposure (safety) for infants and children in the
case of threshold effects to account for pre-and post-natal toxicity
and the completeness of the database unless EPA determines that a
different MOE (safety) will be safe for infants and children. Margins
of exposure (safety) are often referred to as uncertainty (safety)
factors. EPA believes that reliable data support using the standard MOE
(usually 100X for combined inter- and intra-species variability) and
not the additional tenfold MOE when EPA has a complete data base under
existing guidelines and when the severity of the effect in infants or
children or the potency or unusual toxic properties of a compound do
not raise concerns regarding the adequacy of the standard MOE. Based on
current toxicological data requirements, the database for imidacloprid
relative to pre- (provided by rat and rabbit developmental studies) and
post-natal (provided by the rat reproduction study) toxicity is
complete. Further, as noted above, the acute dietary MOE for women 13+
years or older is 480. This large MOE demonstrates that the prenatal
exposure to infants is not a toxicological concern at this time, and
the additional uncertainty factor is not needed to protect the safety
of infants and children.
Both chronic and acute dietary exposure risk assessments assume
100% crop treated and use tolerance level residues for all commodities.
Refinement of these dietary risk assessments by using percent crop
treated and anticipated residue data would greatly reduce dietary
exposure. Therefore, both of these risk assessments are also an over-
estimate of dietary risk. Consideration of anticipated residues and
percent crop treated would likely result in an anticipated residue
contribution (ARC) which would occupy a percent of the RfD that is
likely to be significantly lower than the currently calculated TMRC
value. Additionally, the acute
[[Page 12958]]
dietary MOE would be greater than the current MOE. This provides an
adequate safety factor for children during the prenatal and postnatal
development.
It is unlikely that the dietary risk will exceed 100 percent of the
RfD or that the acute MOE would be greater than the currently
calculated value if, in the future, an additional safety factor is
deemed appropriate, when considered in conjunction with a refined
exposure estimate. Therefore, EPA concludes that there is reasonable
certainty that no harm will result to infants and children from
aggregate exposure to imidacloprid residues.
V. Other Considerations
The metabolism of imidacloprid in plants and animals is adequately
understood for the purposes of these tolerances. There are no Mexican,
Canadian, or Codex maximum residue levels established for residues of
imidacloprid on cucurbits. There is a practical analytical method for
detecting and measuring levels of imidacloprid in or on food with a
limit of detection that allows monitoring of food with residues at or
above the levels set in these tolerances. EPA has provided information
on this method to FDA. The method is available to anyone who is
interested in pesticide residue enforcement from: By mail, Calvin
Furlow, Public Response and Program Resources Branch, Field Operations
Division (7506C), Office of Pesticide Programs, Environmental
Protection Agency, 401 M St. SW., Washington, DC 20460. Office location
and telephone number: Crystal Mall #2, Rm 1128, 1921 Jefferson Davis
Hwy., Arlington, VA 22202, 703-305-5805.
VI. Conclusion
Therefore, a tolerance in connection with the FIFRA section 18
emergency exemptions is established for residues of imidacloprid in/on
cucurbits at 0.2 ppm. This tolerance will expire on March 31, 1998.
VII. Objections and Hearing Requests
The new FFDCA section 408(g) provides essentially the same process
for persons to ``object'' to a tolerance regulation issued by EPA under
new section 408(e) and (l)(6) as was provided in the old section 408
and in section 409. However, the period for filing objections is 60
days, rather than 30 days. EPA currently has procedural regulations
which govern the submission of objections and hearing requests. These
regulations will require some modification to reflect the new law.
However, until those modifications can be made, EPA will continue to
use those procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by May 19, 1997 file written objections to any
aspect of this regulation (including the automatic revocation
provision) and may also request a hearing on those objections.
Objections and hearing requests must be filed with the Hearing Clerk,
at the address given above (40 CFR 178.20). A copy of the objections
and/or hearing requests filed with the Hearing Clerk should be
submitted to the OPP docket for this rulemaking. The objections
submitted must specify the provisions of the regulation deemed
objectionable and the grounds for the objections (40 CFR 178.25). Each
objection must be accompanied by the fee prescribed by 40 CFR
180.33(i). If a hearing is requested, the objections must include a
statement of the factual issues on which a hearing is requested, the
requestor's contentions on such issues, and a summary of any evidence
relied upon by the requestor (40 CFR 178.27). A request for a hearing
will be granted if the Administrator determines that the material
submitted shows the following: There is genuine and substantial issue
of fact; there is a reasonable possibility that available evidence
identified by the requestor would, if established, resolve one or more
of such issues in favor of the requestor, taking into account
uncontested claims or facts to the contrary; and resolution of the
factual issues in the manner sought by the requestor would be adequate
to justify the action requested (40 CFR 178.32). Information submitted
in connection with an objection or hearing request may be claimed
confidential by marking any part or all of that information as
Confidential Business Information (CBI). Information so marked will not
be disclosed except in accordance with procedures set forth in 40 CFR
part 2. A copy of the information that does not contain CBI must be
submitted for inclusion in the public record. Information not marked
confidential may be disclosed publicly by EPA without prior notice.
VIII. Public Docket
A record has been established for this rulemaking under docket
number [OPP-300460]. A public version of this record, which does not
include any information claimed as CBI, is available for inspection
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal
holidays. The public record is located in Room 1132 of the Public
Response and Program Resources Branch, Field Operations Division
(7506C), Office of Pesticide Programs, Environmental Protection Agency,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA.
Electronic comments may be sent directly to EPA at:
opp-docket@epamail.epa.gov.
Electronic comments must be submitted as an ASCII file avoiding the
use of special characters and any form of encryption.
The official record for this rulemaking, as well as the public
version, as described above, is kept in paper form. Accordingly, in the
event there are objections and hearing requests, EPA will transfer any
copies of objections and hearing requests received electronically into
printed, paper form as they are received and will place the paper
copies in the official rulemaking record. The official rulemaking
record is the paper record maintained at the Virginia address in
``ADDRESSES'' at the beginning of this document.
IX. Regulatory Assessment Requirements
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is not a ``significant regulatory action'' and, since this
action does not impose any information collection requirements as
defined by the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., it is
not subject to review by the Office of Management and Budget. This
action does not impose any enforceable duty, or contain any ``unfunded
mandates'' as described in Title II of the Unfunded Mandates Reform Act
of 1995 (Pub. L. 104-4), or require prior consultation as specified by
Executive Order 12875 (58 FR 58093, October 28, 1993), entitled
Enhancing the Intergovernmental Partnership, or special consideration
as required by Executive Order 12898 (59 FR 7629, February 16, 1994).
Because FFDCA section 408(l)(6) permits establishment of this
regulation without a notice of proposed rulemaking, the regulatory
flexibility analysis requirements of the Regulatory Flexibility Act, 5
U.S.C. 604(a), do not apply.
Under 5 U.S.C. 801(a)(1)(A) of the Administrative Procedure Act
(APA) as amended by the Small Business Regulatory Enforcement Fairness
Act of 1996 (Title II of Pub. L. 104-121, 110 Stat. 847), EPA submitted
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 General Accounting Office prior to publication of the
rule in today's Federal Register. This rule is not a ``major rule'' as
defined by 5 U.S.C. 804(2) of the APA as amended.
[[Page 12959]]
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: February 28, 1997.
Peter Caulkins,
Acting Director, Office of Pesticide Programs.
Therefore, 40 CFR Chapter I is amended as follows:
PART 180--[AMENDED]
1. The authority citation for part 180 continues to read as
follows:
Authority: 21 U.S.C. 346a and 371.
2. In Sec. 180.472, in paragraph (d), by adding alphabetically the
following entry to the table:
Sec. 180.472 Imidacloprid; tolerances for residues.
* * * * *
------------------------------------------------------------------------
Parts per Expiration/
Commodity million Revocation Date
------------------------------------------------------------------------
* * * * *
Vegetables, Cucurbits................... 0.2 March 31, 1998
------------------------------------------------------------------------
* * * * *
[FR Doc. 97-6654 Filed 3-18-97; 8:45 am]
BILLING CODE 6560-50-F
