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Lambda-cyhalothrin. October 29, 1997. Pesticide Tolerances for Emergency Exemptions. Final Rule. Federal Register.
http://www.epa.gov/fedrgstr/EPA-PEST/1997/October/Day-29/p28655.htm
[Federal Register: October 29, 1997 (Volume 62, Number 209)]
[Rules and Regulations]
[Page 56095-56102]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29oc97-28]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 180
[OPP-300555; FRL-5745-5]
RIN 2070-AB78
Lambda-cyhalothrin; Pesticide Tolerances for Emergency Exemptions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This regulation establishes time-limited tolerances for
combined residues of lambda-cyhalothrin and its epimer in or on barley
grain, barley bran, barley hay and straw, canola seed, and sugarcane.
This action is in response to EPA's granting of emergency exemptions
under section 18 of the Federal Insecticide, Fungicide, and Rodenticide
Act authorizing use of the pesticide on barley, canola, and sugarcane
in Louisiana and Montana. This regulation establishes maximum
permissible levels for residues of lambda-cyhalothrin in the above-
mentioned food commodities pursuant to section 408(l)(6) of the Federal
Food, Drug, and Cosmetic Act, as amended by the Food Quality Protection
Act of 1996.
DATES: This regulation is effective October 29, 1997. Objections and
requests for hearings must be received by EPA on or before December 29,
1997.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, OPP-300555, 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-300555],
must also be submitted to: Public Information and Records Integrity
Branch, Information Resources and Services Division (7502C), 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 Hwy., 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. 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-
300355. 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.
[[Page 56096]]
FOR FURTHER INFORMATION CONTACT: By mail: Virginia Dietrich,
Registration Division (7505C), Office of Pesticide Programs,
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
Office location, telephone number, and e-mail address: Crystal Mall #2,
1921 Jefferson Davis Hwy., Arlington, VA, (703) 308-9359, e-mail:
dietrich.virginia@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: EPA, on its own initiative, 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
combined residues of the insecticide lambda-cyhalothrin and its epimer,
in or on barley grain, barley bran, barley hay and straw, canola seed
and sugarcane at 0.05, 0.2, 2.0, 0.10, and 0.03 part per million (ppm),
respectively. These tolerances will expire and are revoked on August
30, 1998. EPA will publish a document in the Federal Register to remove
the revoked tolerances from the Code of Federal Regulations.
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 Federal
Insecticide, Fungicide, and Rodenticide Act (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 FR 58135, November 13, 1996) (FRL-5572-9).
New 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) 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)
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) 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.
Because decisions on section 18-related tolerances must proceed
before EPA reaches closure on several policy issues relating to
interpretation and implementation of the FQPA, EPA does not intend for
its actions on such tolerance to set binding precedents for the
application of section 408 and the new safety standard to other
tolerances and exemptions.
II. Emergency Exemption for Lambda-cyhalothrin on Barley, Canola,
and Sugarcane and FFDCA Tolerances
Cutworms are serious pests of small grains in Montana. Infestations
can result in severe damage from the voracious feeding by the larvae.
Since the cancellation of endrin, barley production has remained
unprotected with an effective registered chemical. Unusually high
levels of moths caught during Montana fall cutworm surveys demonstrated
the potential for infestation at levels that could result in
significant economic losses. This spring, levels of cutworm infestation
exceeded the threshold for treatment and the Montana Department of
Agriculture declared a crisis exemption on May 16, 1997.
Feeding on canola by Diamondback moth larvae is expected to result
in economically significant losses of 40% in canola grown in Montana
unless adequately controlled. A rapid knock-down of the larvae is
necessary to prevent significant yield loss which occurs within 2 or 3
days after the larvae begin feeding on the seed pod. The registered
alternatives, endosulfan and methyl parathion, both take a week or
longer to match the efficacy of lambda-cyhalothrin. Another
alternative, ethyl parathion, while effective in controlling this pest,
is unavailable to most canola growers in Montana because there are few
commercial applicators with the required closed loading system.
Sugarcane yield loss from the sugarcane borer is estimated at 60%
unless adequately controlled. Registered alternatives either are more
toxic to aquatic environments or cause secondary outbreaks of aphids
due to toxicity to non-target arthropods (parasites and predators).
After having reviewed these submissions, EPA concurs that emergency
conditions exist for these states. EPA has authorized under FIFRA
section 18 the use of lambda-cyhalothrin on barley, canola, and
sugarcane for control of cutworm in barley, Diamondback moth in canola,
and Sugarcane borer in sugarcane in Montana and Louisiana.
As part of its assessment of this emergency exemption, EPA assessed
the potential risks presented by residues of lambda-cyhalothrin in or
on barley, canola, and sugarcane. In doing so, EPA considered the new
safety standard in FFDCA section 408(b)(2), and EPA decided that the
necessary tolerance under FFDCA section 408(l)(6) would be consistent
with the new 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 under section 408(e), as provided in
section 408(l)(6). Although this tolerance will expire and is revoked
on August 30, 1998, under FFDCA section 408(l)(5), residues of the
pesticide not in excess of the amounts specified in the tolerance
remaining in or on barley, canola, and sugarcane after that date will
not be unlawful, provided the pesticide is applied in a manner that was
lawful under FIFRA. 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.
Because this tolerance is being approved under emergency
conditions, EPA has not made any decisions about whether lambda-
cyhalothrin meets EPA's registration requirements for use on barley,
canola, and sugarcane or whether a permanent tolerance for this use
would be appropriate. Under these circumstances, EPA does not believe
that this tolerance serves as a basis for
[[Page 56097]]
registration of lambda-cyhalothrin by a State for special local needs
under FIFRA section 24(c). Nor does this tolerance serve as the basis
for any State other than Montana and Louisiana to use this pesticide 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 exemption for lambda-cyhalothrin, 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. Second,
EPA examines exposure to the pesticide through the diet (e.g., food and
drinking water) and through exposures that occur as a result of
pesticide use in residential settings.
A. Toxicity
1. Threshold and non-threshold effects. For many animal studies, a
dose response relationship can be determined, which provides a dose
that 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% or less of the RfD) is
generally considered acceptable by EPA. EPA generally uses the RfD to
evaluate the chronic risks posed by pesticide exposure. For shorter
term risks, EPA calculates a margin of exposure (MOE) by dividing the
estimated human exposure into the NOEL from the appropriate animal
study. Commonly, EPA finds MOEs lower than 100 to be unacceptable. This
100-fold MOE is based on the same rationale as the 100-fold uncertainty
factor.
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
relationship. Once a pesticide has been classified as a potential human
carcinogen, different types of risk assessments (e.g., linear low dose
extrapolations or MOE 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.
2. Differences in toxic effect due to exposure duration. The
toxicological effects of a pesticide can vary with different exposure
durations. EPA considers the entire toxicity data base, and based on
the effects seen for different durations and routes of exposure,
determines which risk assessments should be done to assure that the
public is adequately protected from any pesticide exposure scenario.
Both short and long durations of exposure are always considered.
Typically, risk assessments include ``acute,'' ``short-term,''
``intermediate term,'' and ``chronic'' risks. These assessments are
defined by the Agency as follows.
Acute risk, by the Agency's definition, results from 1-day
consumption of food and water, and reflects toxicity which could be
expressed following a single oral exposure to the pesticide residues.
High end exposure to food and water residues are typically assumed.
Short-term risk results from exposure to the pesticide for a period
of 1-7 days, and therefore overlaps with the acute risk assessment.
Historically, this risk assessment was intended to address primarily
dermal and inhalation exposure which could result, for example, from
residential pesticide applications. However, since enaction of FQPA,
this assessment has been expanded to include both dietary and non-
dietary sources of exposure, and will typically consider exposure from
food, water, and residential uses when reliable data are available. In
this assessment, risks from average food and water exposure, and high-
end residential exposure, are aggregated. High-end exposures from all
three sources are not typically added because of the very low
probability of this occurring in most cases, and because the other
conservative assumptions built into the assessment assure adequate
protection of public health. However, for cases in which high-end
exposure can reasonably be expected from multiple sources (e.g.
frequent and widespread homeowner use in a specific geographical area),
multiple high-end risks will be aggregated and presented as part of the
comprehensive risk assessment/characterization. Since the toxicological
endpoint considered in this assessment reflects exposure over a period
of at least 7 days, an additional degree of conservatism is built into
the assessment; i.e., the risk assessment nominally covers 1-7 days
exposure, and the toxicological endpoint/NOEL is selected to be
adequate for at least 7 days of exposure. (Toxicity results at lower
levels when the dosing duration is increased.)
Intermediate-term risk results from exposure for 7 days to several
months. This assessment is handled in a manner similar to the short-
term risk assessment.
Chronic risk assessment describes risk which could result from
several months to a lifetime of exposure. For this assessment, risks
are aggregated considering average exposure from all sources for
representative population subgroups including infants and children.
B. Aggregate Exposure
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, residues in groundwater
or surface water that is consumed as drinking water, and other non-
occupational exposures through pesticide use in gardens, lawns, or
buildings (residential and other indoor uses). 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. In
[[Page 56098]]
evaluating food exposures, EPA takes into account varying consumption
patterns of major identifiable subgroups of consumers, including
infants and children. 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% 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.
Percent of crop treated estimates are derived from federal and
private market survey data. Typically, a range of estimates are
supplied and the upper end of this range is assumed for the exposure
assessment. By using this upper end estimate of percent of crop
treated, the Agency is reasonably certain that exposure is not
understated for any significant subpopulation group. Further, regional
consumption information is taken into account through EPA's computer-
based model for evaluating the exposure of significant subpopulations
including several regional groups, to pesticide residues. For this
pesticide, the most highly exposed population subgroup (non-nursing
infants less than 1 year old) was not regionally based.
IV. Aggregate Risk Assessment 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. EPA has sufficient data to assess the hazards of lambda-
cyhalothrin and to make a determination on aggregate exposure,
consistent with section 408(b)(2), for a time-limited tolerance for
combined residues of lambda-cyhalothrin and its epimer on barley grain,
barley bran, barley hay and straw, canola seed and sugarcane at 0.05,
0.2, 2, 0.10, and 0.03 ppm, respectively. EPA's assessment of the
dietary exposures and risks associated with establishing the tolerance
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. The nature of the toxic effects caused by lambda-cyhalothrin
are discussed below.
1. Acute toxicity. EPA's Office of Pesticide Programs (OPP) is
currently reassessing time-limited tolerances for residues of lambda-
cyhalothrin in or on over a dozen commodities established for
conditional registrations. These tolerances are due to expire November
15, 1997. On July 31, 1997, as part of this reassessment, the OPP's
Hazard Identification Assessment Review Committee identified an acute
toxicity endpoint and recommended use of the NOEL of 0.5 mg/kg/day for
an acute dietary endpoint, based on gait abnormalities in dogs in a 1
year oral toxicity study. The following assessment for the tolerances
in this document uses this recommended endpoint of concern as a basis
to evaluate acute dietary risk to population subgroups.
2. Short - and intermediate-term toxicity. For short- and
intermediate-term margin of exposure (MOE) calculations, EPA's Office
of Pesticide Programs (OPP) selected use of the NOEL of 0.3 ug/l (0.05
milligrams/kilogram/day (mg/kg/day) from the 21-day inhalation toxicity
study in rats. The LEL of 3.3 ug/l was based on decreased body weight
gains and clinical signs of toxicity including paw flicking, tail
erections, and tiptoe gait.
In the 21-day dermal toxicity study, the NOEL was >1000 mg/kg/day
(limit dose) and therefore the Office of Pesticide Programs did not
select an endpoint.
3. Chronic toxicity. EPA has established the RfD for lambda-
cyhalothrin at 0.001 mg/kg/day. This RfD is based on a 1-year oral
study in dogs with a NOEL of 0.1 mg/kg/day and an uncertainty factor
(UF) of 100. The LEL of 0.5 mg/kg/day was based on clinical signs of
neurotoxicity (convulsions, ataxia, muscle tremors) and a slight
increase in liquid feces.
4. Carcinogenicity. Lambda-cyhalothrin has been classified by the
Office of Pesticide Programs as a Group ``D'' chemical, ``not
classifiable as to human carcinogenicity.''
B. Exposures and Risks
1. From food and feed uses. Tolerances have been established (40
CFR 180.438, 185.3765, and 186.3765) for the combined residues of
lambda-cyhalothrin and its epimer, in or on a variety of raw
agricultural commodities at levels ranging from 0.01 to 6.0 ppm. A food
additive tolerance has been established under 40 CFR 185.1310 for
residues on dried hops. Tolerances with the expiration date of November
15, 1997, have been established under 40 CFR 185.3765 for sunflower
hulls, corn grain flour, and tomato pomace. Time-limited tolerances
have been established for various animal products under 40 CFR
185.3765. Risk assessments were conducted by EPA to assess dietary
exposures and risks from lambda-cyhalothrin as follows:
i. Acute exposure and risk. The registrant, Zeneca Ag Products, has
submitted a ``Monte Carlo'' analysis assessing acute dietary risk for
lambda-cyhalothrin to support extension of tolerances due to expire in
November 1997. The results of the analysis are summarized below.
Table 1.--Acute Dietary Exposure and Risk Analysis Results
------------------------------------------------------------------------
Exposure (mg/kg/
Population day) 99.9th MOE 99.9th
percentile percentile
------------------------------------------------------------------------
U.S. Population 0.002108 237
Children 1 - 6 Years 0.003789 132
Children 7 - 12 Years 0.001893 264
Non-Nursing Infants 0.003281 152
Nursing Infants 0.000969 516
Women, 13+ Years 0.000831 601
------------------------------------------------------------------------
The Monte Carlo analysis provided by the registrant has not
undergone a thorough review in the Agency. However, given the emergency
nature of the section 18 requests, the Agency will consider the results
of the registrant's analysis to support the section 18 use of lambda-
cyhalothrin on barley, canola, and sugarcane.
ii. Chronic exposure and risk. The existing lambda-cyhalothrin
tolerances plus the proposed section 18 use resulted in an Anticipated
Residue Contribution (ARC) that is equivalent to the following
percentages of the RfD:
U.S Population--22%
Nursing Infants (<1 year old)--25%
Non-Nursing Infants (<1 year old)--71%
Children (1-6 years old)--50%
Children (7-12 years old)--33%
Hispanics--25%
Non-Hispanic Others--27%
Northeast Region--23%
Western Region--24%
The subgroups listed above are: (1) The U.S. population (48
states); (2) those for infants and children; and (3)
[[Page 56099]]
the other subgroups for which the percentage of the RfD occupied is
greater than that occupied by the subgroup U.S. population (48 states).
Further refinement using percent crop-treated data for all commodities
would result in lower dietary exposure estimates.
2. From drinking water. Office of Pesticide Program studies
indicate lambda-cyhalothrin is moderately persistent and mobile in
surface water, but not ground water. There is no established Maximum
Contaminant Level (MCL) for residues of lambda-cyhalothrin in drinking
water. No health advisory levels for lambda-cyhalothrin in drinking
water have been established. There is no entry for lambda-cyhalothrin
in the ``Pesticides in Groundwater Database.''
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 exposure
from contaminated water, the ranges the Agency is continuing to examine
are all below the level that would cause lambda-cyhalothrin 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 lambda-cyhalothrin 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.
3. From non-dietary exposure. Lambda-cyhalothrin is currently
registered for use on the following residential non-food sites: general
pest control (crack/crevice/spot), termiticide, landscape, turf
ornamentals, commercial ornamentals, golf course turf, and unoccupied
agricultural premises.
The Agency lacks sufficient residential-related exposure data to
complete a comprehensive residential risk assessment for many
pesticides, including lambda-cyhalothrin. However, because: (1) Lambda-
cyhalothrin has a low vapor pressure (2 x 10<SUP>-10</SUP> torr); (2)
no acute toxicity endpoints were identified by the Toxicity End-Point
Selection Committee; (3) no short- or intermediate-term dermal toxicity
endpoint was identified; (4) for occupationally exposed workers, high
MOEs for inhalation exposure were calculated (ranging from 1,200 to
13,000); and (5) the low percentage of the RfD that is occupied for the
general population by the pending and registered uses of this chemical;
in the best scientific judgement of OPP, non-dietary, non-occupational
uses of lambda-cyhalothrin should not pose a risk that exceeds OPP's
level of concern.
4. Cumulative exposure to substances with a 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 mechanisms 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 lambda-cyhalothrin has a common mechanism of toxicity with
other substances or how to include this pesticide in a cumulative risk
assessment. For the purposes of this tolerance action, therefore, EPA
has not assumed that lambda-cyhalothrin has a common mechanism of
toxicity with other substances.
C. Aggregate Risks and Determination of Safety for U.S. Population
1. Acute risk. OPP has concluded that exposure from existing uses
results in MOE estimates that are not likely to exceed the Agency's
acceptable level (less than 100) for acute exposure. OPP also believes
adding the proposed section 18 tolerances would still result in
acceptable MOEs. Therefore, the Agency has concluded that these new
temporary tolerances meet the reasonable certainty of no harm finding
for acute risk. A discussion of the factors considered for this
decision follows.
Emergency exemptions for three commodities, sugarcane, barley, and
canola, were issued earlier this year. At that time, no acute exposure
endpoint had been identified in the Agency's risk assessment for the
emergency exemption. However, as a result of review of new data
submitted to support the extension of temporary tolerances established
for conditional registrations, an acute exposure endpoint for lambda-
cyhalothrin was identified (see Unit IV.A.1. of this document). OPP
therefore revisited the acute risk assessment for the emergency
exemptions. A preliminary review of the new information using the
Agency's best professional judgement supported the reasonable certainty
of no harm finding. EPA's conclusions regarding this risk analysis may
change following a more thorough review.
[[Page 56100]]
The basis for this risk assessment is an acute dietary exposure
analysis using a ``Monte Carlo'' model which reflects the distribution
of possible residues on the commodities considered in the analysis as
well as percent of crop treated information. This model was applied to
both food and feed commodities covered under existing temporary
tolerances. Although this analysis did not consider the commodities
treated under the emergency exemption, the Agency believes that these
tolerances are adequately protective for the following two reasons.
Direct consumption of lambda-cyhalothrin through these commodities
(barley, sugarcane, and canola) is expected to be lower than tolerance
levels since the commodities are consumed as the processed product and
not as the raw agricultural commodity. Exposure from secondary
residues, those consumed through eating products from animals fed these
raw agricultural commodities, is nearly all accounted for because the
current analysis includes wheat, corn, and rice as well as peanut oil,
corn oil, cottonseed oil, and soybean oil. These items comprise a much
greater portion of animals diets than do barley, canola, or sugarcane.
2. Chronic risk. Using the ARC exposure assumptions described
above, EPA has concluded that aggregate exposure to lambda-cyhalothrin
from food will utilize 22 percent of the RfD for the U.S. population.
The major identifiable subgroup with the highest aggregate exposure is
Non-Nursing Infants (<1 year old) and is discussed later in this
document under Determination of Safety for Infants and Children. EPA
generally has no concern for exposures below 100% 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 lambda-cyhalothrin in
drinking water and from non-dietary, non-occupational exposure, 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 lambda-cyhalothrin residues.
3. Short- and intermediate-term risk. Short- and intermediate-term
aggregate exposure takes into account chronic dietary food and water
(considered to be a background exposure level) plus indoor and outdoor
residential exposure.
D. Aggregate Cancer Risk for U.S. Population
Lambda-cyhalothrin has been classified by OPP as a Group ``D''
chemical, ``not classifiable as to human carcinogenicity.'' For this
reason, this risk assessment was not considered appropriate and was not
conducted.
E. Aggregate Risks and Determination of Safety for Infants and Children
1. Safety factor for infants and children-- a. In general. In
assessing the potential for additional sensitivity of infants and
children to residues of lambda-cyhalothrin, EPA considered data from
developmental toxicity studies in the rat and rabbit and a two-
generation reproduction study in the rat. The developmental toxicity
studies are designed to evaluate adverse effects on the developing
organism resulting from maternal pesticide exposure during gestation.
Reproduction studies provide information relating to effects from
exposure to the pesticide on the reproductive capability of mating
animals and data on systemic toxicity.
FFDCA section 408 provides that EPA shall apply an additional 10-
fold margin of safety for infants and children in the case of threshold
effects to account for pre-and post-natal toxicity and the completeness
of the data base 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. EPA
believes that reliable data support using the standard uncertainty
factor (usually 100 for combined inter- and intra-species variability)
and not the additional 10-fold uncertainty factor 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 safety factor.
b. Developmental toxicity studies--i. Rats. From the developmental
toxicity study in rats, the maternal (systemic) NOEL was 10 mg/kg/day.
The maternal LEL of 15 mg/kg/day was based on decreased body weight
gain and decreased food consumption. The developmental (fetal) NOEL was
>15 mg/kg/day at the highest dose tested (HDT).
2. Rabbit. From the developmental toxicity study in rabbits, the
maternal (systemic) NOEL was 10 mg/kg/day. The maternal LEL of 30 mg/
kg/day was based on decreased body weight gain. The developmental
(fetal) NOEL was >30 mg/kg/day (HDT).
c. Reproductive toxicity study--Rats. From the 3-generation
reproductive toxicity study in rats, both the parental (systemic) and
reproductive (pup) NOELs were 1.5 mg/kg/day. Both the parental
(systemic) and reproductive (pup) LELs were 5 mg/kg/day. They were
based on a significant decrease in parental body weight (systemic) or a
significant decrease in pup body weight (reproductive). The
developmental NOEL was 5 mg/kg/day (HDT).
d. Pre- and post-natal sensitivity. The toxicology data base for
lambda-cyhalothrin is complete with respect to current toxicological
data requirements. There are no pre- or post-natal toxicity concerns
for infants and children, based on the results of the rat and rabbit
developmental toxicity studies and the 3-generation reproductive
toxicity study in rats.
e. Conclusion. Based on the above, EPA concludes that reliable data
support the use of the standard 100-fold margin of uncertainty factor
and that an additional uncertainty factor is not warranted at this
time.
2. Acute risk. OPP has concluded that exposure from existing uses
results in MOE estimates that are not likely to exceed the Agency's
acceptable level (less than 100) for acute exposure. OPP also believes
adding the proposed section 18 tolerances would still result in
acceptable MOEs. Therefore, the Agency has concluded that these new
temporary tolerances meet the reasonable certainty of no harm finding
for acute risk. A discussion of the factors considered for this
decision can be found in Unit IV.C.1. of this preamble.
3. Chronic risk. Using the conservative exposure assumptions
described above, EPA has concluded that aggregate exposure to lambda-
cyhalothrin from food will utilize from 25% for nursing infants less
than 1 year old, up to 71% for non-nursing infants less than 1 year old
of the RfD for infants and children. EPA generally has no concern for
exposures below 100% 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 lambda-cyhalothrin in drinking water and from non-dietary,
non-occupational exposure, 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 to infants and
[[Page 56101]]
children from aggregate exposure to lambda-cyhalothrin residues.
V. Other Considerations
A. Metabolism in Plants and Animals
OPP has determined that the nature of the residue in plants and
animals is adequately understood based on metabolism studies conducted
on cotton, cabbage, soybeans, and wheat. The residue of concern is
lambda-cyhalothrin and its epimer.
B. Analytical Enforcement Methodology
Adequate methods are available for the enforcement of the current
tolerance expression. The analytical method (GC/ECD) for determination
of lambda-cyhalothrin is ICI Method 81 which has been validated by the
Agency and was found to be adequate for regulatory purposes.
The petitioner has determined recoveries of lambda-cyhalothrin and
its metabolites PP890, and 3-PBAcid under FDA's multi-residue
protocols.
C. Magnitude of Residues
Time-limited tolerances for combined residues of lambda-cyhalothrin
and its epimer should be established as follows to support this section
18 exemption:
Barley, grain--0.05 ppm
Barley, bran--0.2 ppm
Barley, straw--2 ppm
Barley, hay--2 ppm
Canola seed--0.10 ppm
Sugarcane--0.03 ppm
Barley grain, straw, and hay are livestock feed items. The dietary
burden resulting from potential lambda-cyhalothrin residues in/on
barley feedstuffs is comparable to that resulting from other livestock
feedstuffs which have lambda-cyhalothrin tolerances (such as corn
forage at 1.0 ppm and corn grain at 0.05 ppm). Thus, secondary residues
in animal commodities are not expected to exceed existing tolerances as
a result of this section 18 use.
D. International Residue Limits
There are no Codex, Canadian, or Mexican maximum residue limits
(MRLs) for residues of lambda-cyhalothrin in/on barley. Therefore,
international harmonization is not an issue for this section 18 use.
E. Rotational Crop Restrictions
Studies submitted in support of lambda-cyhalothrin registration
showed that significant residues (<0.01 ppm) will not be present in
crops rotated 30 days after application of parent lambda-cyhalothrin.
No additional rotational crop data are needed to support current
registered application rates.
VI. Conclusion
Therefore, the tolerance is established for combined residues of
lambda-cyhalothrin and its epimer in barley grain, barley bran, barley
hay and straw, canola seed and sugarcane at 0.05, 0.2, 2, 0.10, and
0.03 ppm, respectively.
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 December 29, 1997, file written objections to
any aspect of this regulation 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 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
EPA has established a record for this rulemaking under docket
control number OPP-300555 (including any comments and data submitted
electronically). A public version of this record, including printed,
paper versions of electronic comments, 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 Information and Records
Integrity Branch, Information Resources and Services Division (7502C),
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 will be kept in paper form. Accordingly,
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 which
will also include all comments submitted directly in writing. 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
This final rule establishes time-limited tolerances under FFDCA
section 408(l)(6). 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). 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
[[Page 56102]]
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA) (Pub. L.
104-4). Nor does it require any prior consultation as specified by
Executive Order 12875, entitled Enhancing the Intergovernmental
Partnership (58 FR 58093, October 28, 1993), or special considerations
as required by Executive Order 12898, entitled Federal Actions to
Address Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994), or require OMB review in
accordance with Executive Order 13045, entitled Protection of Children
from Environmental Health Risks and Safety Risks (62 FR 19885, April
23, 1997).
In addition, since these tolerances and exemptions that are
established on the basis of a petition under FFDCA section 408(l)(6),
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. Nevertheless, the Agency has
previously assessed whether establishing tolerances, exemptions from
tolerances, raising tolerance levels or expanding exemptions might
adversely impact small entities and concluded, as a generic matter,
that there is no adverse economic impact. The factual basis for the
Agency's generic certification for tolerance actions published on May
4, 1981 (46 FR 24950), and was provided to the Chief Counsel for
Advocacy of the Small Business Administration.
X. Submission to Congress and the General Accounting Office
Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business
Regulatory Enforcement Fairness Act of 1996, the Agency has 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 this rule in
today's Federal Register. This 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: October 21, 1997.
James Jones,
Acting Director, Registration Division, 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. 180.438, by adding paragraph (b) to read as follows:
Sec. 180.438 Lambda-cyhalothrin tolerance for residues.
* * * * *
(b) Section 18 emergency exemptions. Time-limited tolerances are
established for combined residues of the insecticide lambda-cyhalothrin
(a 1:1 mixture of (S)-<greek-a>-cyano-3-phenoxybenzyl-(Z)-(1R,3R)-3-(2-
chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate
and (R)-<greek-a>-cyano-3-phenoxybenzyl-(Z)-(1S,3S)-3-(2-chloro-3,3,3-
trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate and its
epimer a 1:1 mixture of (S)-<greek-a>-cyano-3-phenoxybenzyl-(Z)-
(1S,3S)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclo-
propanecarboxylate and (R)-<greek-a>-cyano-3-phenoxybenzyl (Z)-(1R,3R)-
3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclo-
propanecarboxylate in connection with use of the pesticide under
section 18 emergency exemptions granted by EPA. The tolerances will
expire and are revoked on the dates specified in the following table.
------------------------------------------------------------------------
Expiration/
Commodity Parts per million Revocation Date
------------------------------------------------------------------------
barley bran 0.2 8/30/98
barley grain 0.05 8/30/98
barley hay 2 8/30/98
barley straw 2 8/30/98
canola seed 0.1 8/30/98
sugarcane 0.03 8/30/98
------------------------------------------------------------------------
* * * * *
[FR Doc. 97-28655 Filed 10-28-97; 8:45 am]
BILLING CODE 6560-50-F