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Cyfluthrin (Bayer). May 9, 1997, Pesticide Tolerance. Final Rule. Federal Register.
http://www.epa.gov/fedrgstr/EPA-PEST/1997/May/Day-09/p12195.htm
[Federal Register: May 9, 1997 (Volume 62, Number 90)]
[Rules and Regulations]
[Page 25518-25524]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09my97-19]
[[Page 25518]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 180
[OPP-300484; FRL-5715-6]
RIN 2070-AB78
Cyfluthrin; Pesticide Tolerance
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final Rule.
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SUMMARY: This regulation establishes time-limited tolerances with an
expiration date of November 15, 1997 for residues of the pyrethroid
cyfluthrin in or on the food commodities group citrus fruit and a
maximum residue limit for cyfluthrin on citrus oil and dried pulp. A
petition was submitted by Bayer Corporation to EPA under the Federal
Food Drug and Cosmetic Act (FFDCA) as amended by the Food Quality
Protection Act of 1996 (Pub. L. 104-170) requesting the tolerance. This
tolerance will expire and is revoked on November 15, 1997.
DATES: This regulation becomes effective May 9, 1997. Written
objections and requests for hearings must be received by July 8, 1997.
ADDRESSES: Written objections and hearing requests, identified by the
docket control number, [OPP-300484], 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-300484], should 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 Hwy., Arlington.
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 number
[OPP-300484]. 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: George T. LaRocca, Product
Manager (PM) 13, Registration Division (7505C), Office of Pesticide
Programs, Environmental Protection Agency, 401 M St., SW., Washington,
DC 20460. Office location and telephone number: Rm. 204, CM #2, 1921
Jefferson Davis Highway, Arlington, VA, (703) 305-6100, e-mail:
larocca.george@epamail.epa.gov.
SUPPLEMENTARY INFORMATION: EPA issued a notice, published in the July
13, 1994 Federal Register (59 FR 35717)(FRL-4871-5), which announced
that Miles Corporation had submitted a pesticide petition (4F4313) to
EPA and a food/feed additive petition (FAP) 4H5687 to EPA. Pesticide
petition 4F4313 requests that the Administrator, pursuant to section
408(d) of the Federal Food, Drug an Cosmetic Act, 21 U.S.C. 346a(d),
amend 40 CFR 180.436 to establish tolerances for residues of the
insecticide cyfluthrin, ([cyano-[4-fluoro-3-phenoxyphenyl]-methyl-3-
[2,2-dicloroethenyl]-2,2-dimethylcyclopropanecarboxylate]; CAS No.
68359-37-5; EPA Chemical No. 128831) in or on the food commodities
group citrus, fruits at 0.2 parts per million (ppm). Food/feed additive
petition 4H5687 requests that the Administrator, pursuant to section
409(e) of the FFDCA (21 U.S.C. 348), amend 40 CFR parts 185 and 186 by
establishing a food/feed additive regulation for cyfluthrin in or on
the process commodities citrus oil and citrus dried pulp at 0.3 ppm.
The Agency was unable to publish a final rule prior to the enactment of
the Food Quality and Protection Act (FQPA) of 1996. Because of new
procedures under FQPA Bayer Corporation was required to submit a new
notice of filing requesting issuance of these tolerances in compliance
with FQPA.
In the Federal Register of March 14, 1997 (62 FR 12182)(FRL-5990-2)
EPA issued a second notice of filing to bring the notice into
conformity with the FQPA. The notice contained a summary of the
petition prepared by the petitioner and this summary contained
conclusions and assessments to support its conclusion that the petition
complied with FQPA.
There were no comments received in response to the notices of
filing.
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.
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 408(b)(2)(D) specifies factors EPA is to consider
in establishing a tolerance. Section 408(b)(3) requires EPA to
determine that there is a practical method for detecting and measuring
levels of the pesticide chemical residue in or on food and that the
tolerance be set at a level at or above the limit of detection of the
designated method. Section 408(b)(4) requires EPA to determine whether
a maximum residue level has been established for the pesticide chemical
by the Codex Alimentarius Commission. If so, and EPA does not propose
to adopt that level, EPA must publish for public comment a notice
explaining the reasons for departing from the Codex level.
II. 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
[[Page 25519]]
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 causes adverse effects (threshold effects) and doses
causing no observed effects (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
significant 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 acceptable by EPA.
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 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, FQPA 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.
Consistent with sections 408(b)(2)(C) (D), EPA has reviewed the
available scientific data and other relevant information in support of
this action. EPA has also assessed the toxicology data base for
cyfluthrin its evaluation of application for registration on citrus.
EPA has sufficient data to assess the hazards of cyfluthrin and to make
a determination on aggregate exposure, consistent with section
408(b)(2), for granting time-limited tolerances for residues of
cyfluthrin on citrus at 0.2 ppm, and citrus oil and dried pulp at 0.3
ppm. EPA's assessment of the database, dietary exposures and risks
associated with establishing these tolerances follows:
A. Toxicology Database
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 cyfluthrin are
discussed below.
1. Acute studies. A battery of acute toxicity studies placing
technical cyfluthrin in toxicity category II.
2. Chronic studies. i. A 12-month chronic feeding study in dogs
with a no-observed effect level (NOEL) of 4 milligram per kilogram per
day (mg/kg/day). The lowest effect level (LEL) for this study is
established at 16 mg/kg/day, based on slight ataxia, increased
vomiting, diarrhea and decreased body weight.
ii. A 24-month chronic feeding/carcinogenicity study in rats with a
NOEL of 2.5 mg/kg/day and LEL of 6.2 mg/kg/day, based on decreased body
weights in males, decreased food consumption in males, and inflammatory
foci in the kidneys in females.
iii. A 24-month carcinogenicity study in mice. There were no
carcinogenic effects observed under the conditions of the study.
3. Developmental and reproductive effects studies. i. An oral rat
developmental toxicity study, the maternal (systemic) NOEL is 3 mg/kg/
day. The maternal (systemic) lowest observed effect level (LOEL) of 10
mg/kg/day was based on behavioral changes in gait and coordination. The
developmental (fetal) NOEL is 30 mg/kg/day (highest dose tested). No
developmental effects were noted.
ii. An oral rat developmental toxicity study, the maternal
(systemic) NOEL is 10 mg/kg/day (highest dose tested). The
developmental (fetal) NOEL is 10 mg/kg/day (highest dose tested). No
developmental effects were noted.
iii. A rat inhalation developmental toxicity study, the maternal
(systemic) NOEL is 0.46 mg/m3. The maternal (systemic) LOEL
2.55 mg/m3 was based on decreased body weight gain and
reduced food efficiency. The developmental (fetal) NOEL is 0.46 mg/
m3. The developmental (fetal) LOEL of 2.55 mg/m3
is based on reduced fetal and placental weight, reduced ossification in
the phalanges, metacarpals and vertebrae.
iv. An oral rabbit developmental toxicity study, the maternal
(systemic) NOEL is 20 mg/kg/day. The maternal (systemic) LOEL of 60 mg/
kg/day was based on decreased body weight gain and food consumption
during the dosing period. The developmental (fetal) NOEL is 20 mg/kg/
day. The developmental (fetal) LOEL is 60 mg/kg/day based on
statistically significant increase in the numbers of resorptions and
statistically significant post-implantation loss.
v. An oral 3-generation reproduction study, the systemic NOEL is
1.5 mg/kg/day. The systemic LOEL of 4.5 mg/kg/day was based on body
weight decrease in pups. The reproductive (fetal) NOEL is 4.5 mg/kg/
day. The reproductive (fetal) LOEL is 7.5 mg/kg/day based on decreased
pup viability.
[[Page 25520]]
4. Other studies. i. Mutagenicity tests were conducted, including
several gene mutation assays (reverse mutation and recombination assays
in bacteria and a Chinese hamster ovary(CHO)/HGPRT assay); a structural
chromosome aberration assay (CHO/sister chromatid exchange assay); and
an unscheduled DNA synthesis assay in rat hepatocytes. All tests were
negative for genotoxicity.
ii. A metabolism study in rats showed that cyfluthrin is rapidly
absorbed and excreted, mostly as conjugated metabolites in the urine,
within 48 hours. An enterohepatic circulation was observed. The NOEL
for dermal and systemic toxicity was 1,000 mg/kg/day (limit dose). New
Zealand White strain rabbits were given 15 dermal applications at 0,
100, 500, or 1,000 mg/kg/day for 21 days. Under the conditions of the
test, there was no evidence of treatment-related toxicity from dermal
application at doses up to 1,000 mg/kg/day.
The toxicity database for cyfluthrin is essentially complete. Data
lacking but desirable are a new 21-day subchronic dermal study, an
acute neurotoxicity study in rats, a 90-day neurotoxicity study in
rats, and a dermal sensitization study on the end-use product,
Baythroid 2. These studies have been submitted to the Agency and are
currently under review, with the exception of the acute and 90-day
neurotoxicity studies. Bayer Corporation has committed to submit the
results of these neurotoxicity studies to the Agency by July 1997.
Although these data are lacking, the Agency believes it has sufficient
toxicity data to support the proposed tolerance and these additional
studies will not significantly change its risk assessment.
B. Toxicological Profile
1. Toxicity endpoints for dietary exposure-- i. acute. To assess
acute dietary risk, the Agency used an endpoint of 20 mg/kg/day, the
NOEL from the oral developmental toxicity study in rabbits. This risk
assessment will evaluate acute dietary risk to females 13+ years and
older.
ii. Chronic. A reference dose (RfD) of 0.025 mg/kg/day has been
estimated by the Agency. The RfD was established based on the rat
chronic feeding/carcinogenicity study with a NOEL of 2.5 mg/kg/day and
an uncertainty factor of 100.
iii. Carcinogenicity. Cyfluthrin has been classified as a Group E
chemical (evidence of non-carcinogenicity for humans) by the Agency.
The classification was based on a lack of convincing evidence of
carcinogenicity in adequate studies with two animal species, rat and
mouse.
2. Toxicity endpoints for non-dietary exposure--i. short and
intermediate term residential dermal and/or inhalation exposure. For
short-and intermediate term dermal exposure, the agency used the dermal
toxicity NOEL of 250 mg/kg/day (highest dose tested) from the 21-day
dermal rabbit toxicity study. For short- and intermediate-term
inhalation exposure, the Agency used the inhalation developmental study
in rats, where the maternal threshold NOEL was 0.00046 based on
decreased body weight gain and reduced relative food efficiency at the
LOEL of 0.0025 milligrams per liter (mg/L). The developmental NOEL of
0.00046 mg/l was based on reduced fetal weights, reduced placental
weights, and reduced ossification in the phalanx, metacarpals and
vertebrae at the LOEL of 0.0025 mg/L (0.46 mg/kg/day).
ii. Chronic residential exposure. Based upon the registered indoor/
outdoor uses of cyfluthrin, exposure from these uses are expected to be
from inhalation and/or dermal contact. EPA has no quantitative data on
dermal absorption for the formulations of this pesticide, nor does it
have reliable data for indoor/outdoor exposures. Estimations of outdoor
residential exposure have been required for cyfluthrin in a data call-
in issued in 1995. These data are being generated by the Outdoor
Residential Exposure Task Force. Without these data EPA cannot
determine the risk to the public exposed by the non-dietary uses of
this pesticide. For this reason EPA is using a maximum default
assumption of 20% of the RfD (0.025 mg/kg/day) as the exposure for
these uses.
iii. Dermal penetration. The default value of 100% is being used
for dermal penetration in the absence of actual data.
C. Aggregate Exposure
1. From food and feed uses. The primary source of human exposure
to cyfluthrin will be from ingestion of both raw and processed food
commodities treated with cyfluthrin. These commodities include the
current citrus fruit group plus citrus oil and dried pulp and other
commodities listed in 40 CFR 180.436, 185.1250 and 186.1250. Any
secondary residues occurring in cattle meat, meat byproducts, milk and
fat from the addition of the feed items citrus dried pulp will be
covered by existing tolerances. There is no reasonable expectation of
finite residues in poultry and swine, therefore the necessity or
adequacy of tolerances for these commodities is not an issue relevant
to the use on citrus.
The Agency has requested additional confirmatory animal feeding
study data on levels of the metabolite DCVA (3-(2,2-dichloroethenyl)-
2,2-dimethylcyclopropane carboxylic acid) in animal commodities.
2. From potable (drinking) water. There is no established Maximum
Concentration Level for residues of cyfluthrin in drinking water.
Although data indicate little potential for soil mobility or leaching,
cyfluthrin is moderately persistent. 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 indoor/outdoor residential sites.
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 cyfluthrin 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 cyfluthrin 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 uses. Cyfluthrin is registered for use on non-
food sites including golf courses, lawns, ornamental shrubs, indoor
foggers, and wood surfaces. Upon considering the registered uses,
formulation types, persistence, and toxicological endpoints, and in
accordance with the Agency's Interim Decision Logic (PR
[[Page 25521]]
97-1, Jaunary 31, 1997), EPA has determined that, in the absence of
exposure data, the registered non-dietary, non-occupational uses of
cyfluthrin should be assigned a default value of 20% of the acceptable
aggregate chronic; and short- and intermediate-term risk.
4. Cumulative exposure to substances with common mechanism of
toxicity. Cyfluthrin is a member of the synthetic pyrethroid class of
pesticides. 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).
Although cyfluthrin is structurally similar to other members of the
synthetic pyrethroid class of insecticides, EPA does not have, at this
time, available data to determine whether cyfluthrin 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 cyfluthrin has a
common mechanism of toxicity with other substances.
D. Aggregate Risk Assessment
1. Acute aggregate risk. The acute dietary (food only) risk
assessment used tolerance level residues and assumed 100% crop-treated.
Thus, this acute dietary exposure estimate is considered conservative;
refinement using anticipated residue values and percent crop-treated
data in conjunction with Monte Carlo analysis would result in a lower
acute dietary exposure estimate. A Monte Carlo analysis is a
probabilistic risk assessment methodology in which a distribution of
expected residues (also consumption estimates) is considered, instead
of a single value such as the tolerance level. The estimated acute
dietary risk, using a high-end exposure of 0.03 mg/kg/day, resulted in
an MOE = 666 for the population of concern (females, 13+ years).
The acute aggregate risk assessment takes into account exposure
from dietary food only. As indicated above, although EPA has not
identified a water exposure figure based upon available environmental
data, cyfluthrin is not expected to be mobile in soil or water
environments and poses relatively little threat to drinking water.
Theoretically, it is also possible that a residential, or other non-
dietary, exposure could be combined with the acute total dietary
exposure from food and water. However, the Agency does not believe that
aggregating multiple exposure to large amounts of pesticide residues in
the residential environment via multiple products and routes for a 1
day exposure is a reasonably probable event. It is highly unlikely
that, in 1 day, an individual would have multiple high-end exposures to
the same pesticide by treating their lawn and garden, treating their
house via crack and crevice application, swimming in a pool, and be
maximally exposed in the food and water consumed. Additionally, the
concept of an acute exposure as a single exposure does not allow for
including post-application exposures, in which residues decline over a
period of days after application. Therefore, the Agency believes that
residential exposures are more appropriately included in the short-term
exposure scenario.
An acute dietary MOE of greater than 100 would not be of concern to
EPA. As indicated above, the MOE for females 13+ years was calculated
to be 666. Under any bounding assumption EPA is considering for
exposure from drinking water, this MOE would not be reduced to less
than 100. Therefore, EPA has no acute aggregate concern due to exposure
to cyfluthrin through food and drinking water.
2. Short- and intermediate term aggregate risk. In the absence of
exposure data, EPA is reserving a default value of 20% for residential
exposures. However, as non-quantifiable exposures can not be included
in MOE calculations, the short-term MOE will include only dietary
exposure. Since the short term NOEL is based on a 21 day dermal
exposure toxicity, the dermal exposure will be adjusted for a dietary
endpoint (from the developmental study). The NOEL from the
developmental study (20 mg/kg/day) is 12.5-fold lower than that of the
21-day dermal study (250 mg/kg/day). The adjusted chronic dietary
exposure is thus 0.339 mg/kg/day (TMRC of 0.0271 mg/kg/day multiplied
by 12.5). As the calculated MOE for children (1 to 6 years old) is 737
(short term NOEL of 250 mg/kg/day divided by adjusted dietary exposure
of 0.339 mg/kg/day), the addition of any bounding assumption EPA is
considering for exposures from dietary water and residential sources is
unlikely to result in a MOE of <100. EPA thus considers the short- and
intermediate term risk to be acceptable for the purposes of
establishing the proposed tolerances.
3. Chronic aggregate risk. The chronic dietary (food only) risk
assessment used anticipated residues and percent crop treated for
certain crops. 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 the 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. The resulting
exposure
[[Page 25522]]
estimates should therefore be viewed as partially refined. Further
refinement using anticipated residues and percent crop treated for all
commodities would result in lower dietary exposure estimates. For
chronic dietary (food only) risk estimates, the population subgroup
with the largest percentage of the RfD occupied is children (non-
nursing infants, <1 years old) at 13% of the RfD.
Section 408 (b)(2)(E) requires that, if EPA relies upon anticipated
residue levels in setting a tolerance, EPA must require that data be
submitted 5 years after approval of the tolerance on whether the
anticipated residue level remains accurate. Because this tolerance is
limited to less than 1 year, data are not being required at this time.
The aggregated chronic risk is equal to the sum of the chronic risk
for food, drinking water, and indoor and outdoor residential exposures.
For cyfluthrin, residential exposure data are lacking although the
potential for exposure does exist. Therefore, residential exposure was
also aggregated with dietary exposure in the chronic risk assessment.
The aggregated chronic risk for the population subgroup non-nursing
infants less than 1 year old from combined sources is 33% of the RfD
(dietary = 13% + non-occupational = 20%). Under any bounding
assumptions EPA is considering for exposure from drinking water,
exposure to cyfluthrin would not exceed the RfD. EPA therefore
concludes that there is reasonable certainty that no harm will result
to consumers, including infants and children, from aggregate exposure
to cyfluthrin residues.
4. Determination of safety for infants and children. FFDCA section
408 provides that EPA shall apply an additional tenfold 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
database 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 margin of
exposure analysis or through using uncertainty (safety) factors in
calculating a dose level that poses no appreciable risk to humans. In
either case, EPA generally defines the level of appreciable risk as
exposure that is greater than 1/100 of the NOEL in the animal study
appropriate to the particular risk assessment. This hundredfold
uncertainty (safety) factor/margin of exposure (safety) is designed to
account for combined inter- and intra-species variability. EPA believes
that reliable data support using the standard hundredfold margin/factor
not the additional tenfold margin/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
margin/factor.
In assessing the potential for additional sensitivity of infants
and children to residues of cyfluthrin, EPA considered data from oral
developmental toxicity studies in the rat and rabbit, as well data from
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 the mothers. Reproduction studies provide information
relating to effects from exposure to the pesticide on the reproductive
capability of mating animals and data on systemic toxicity.
5. Pre-natal effects. In the oral rat developmental toxicity
studies, maternal (systemic) effects consisting of behavioral changes
in gait and coordination were the basis of the maternal LOEL of 10 mg/
kg/day. No developmental (fetal) effects were noted in doses up to 30
mg/kg/day (highest dose tested). In the oral rabbit developmental
study, no developmental toxicity was observed at doses where maternal
toxicity was noted. The maternal (systemic) NOEL is 20 mg/kg/day and
the maternal (systemic) LOEL of 60 mg/kg/day was based on decreased
body weight gain and food consumption. The developmental (fetal) NOEL
is 20 mg/kg/day and the developmental (fetal) LOEL of 60 mg/kg/day was
based on increases in the numbers of resorptions and post-implantation
loss.
In an inhalation developmental toxicity study, the maternal
(systemic) and developmental (fetal) NOELs are 0.46 mg/m3
and the maternal (systemic) and developmental (fetal) LOELs are 2.55
mg/m3. The maternal (systemic) LOEL was based on decreased
body weight gain and reduced food efficiency. The developmental (fetal)
LOEL was based on reduced fetal and placental weight and reduced
ossification. The weight of the evidence from this study would suggest
that cyfluthrin exposure caused developmental toxicity indirectly
through bradypnea (abnormal slowness of breathing) in the dams.
6. Post-natal effects. In the rat 2-generation reproduction study,
parental toxicity was observed at 4.5 mg/kg/day based on body weight
decrease in pups (weaned for the next generation). The reproductive
(fetal) NOEL is 4.5 mg/kg/day. The reproductive (fetal) LOEL is 7.5 mg/
kg/day based on decreased pup viability.
These data taken together suggest minimal concern for developmental
or reproductive toxicity and do not indicate any increased pre- or
post-natal sensitivity. Therefore, EPA concludes that reliable data
support use of a hundredfold safety factor, and an additional tenfold
safety factor is not needed to protect the safety of infants and
children.
E. Other Considerations
1. Endocrine effects. No evidence of such effects were reported in
the toxicology studies described above. There is no evidence at this
time that cyfluthrin causes endocrine effects.
2. Metabolism and nature of the residue. The nature of the residue
in plants and animals is adequately understood. The residue of concern
is parent cyfluthrin. Any secondary residues occurring in cattle meat,
meat by-products, milk and fat from the consumption of cyfluthrin
treated citrus will be covered by the existing tolerances for these
commodities.
3. Analytical methodology. Adequate enforcement methodology (gas
chromatography/electron capture detector) for plant and animal
commodities is available to enforce the tolerances. EPA has provided
information on this method to the Food and Drug Adminstration. 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, 703-305-
5805.
4. International tolerances. There are no Codex, Canadian or
Mexican maximum residue limits (MRLs) for residues of cyfluthrin in/on
citrus.
F. Summary of Findings
Tolerances are time-limited to allow for development and review of
supplemental toxicity data; animal feeding data for a metabolite of
cyfluthrin; and residential, water and cumulative exposure data. These
tolerances will expire and be revoked by EPA on November 15, 1997.
After that November 15, 1997, EPA will publish a document in the
Federal Register to remove the revoked tolerances from the Code of
Federal Regulations.
[[Page 25523]]
EPA concludes that the time-limited tolerances will be safe.
Therefore the tolerances are established as set forth.
III. 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
the new section 408(d) 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
given 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 its current procedural regulations with appropriate adjustments to
reflect the new law.
Any person may, by July 8, 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.
IV. Public Docket
The official record for this rulemaking, as well as the public
version, has been established for this rulemaking under docket control
number OPP-300484 (including comments and data submitted electronically
as described below). 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
official rulemaking record is located at the Virginia address in
``ADDRESSES'' at the beginning of this document.
Electronic comments can 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. Comment and data
will also be accepted on disks in Wordperfect 5.1 file format or ASCII
file format. All comments and data in electronic form must be
identified by the docket number OPP-300484. Electronic comments on this
proposed rule may be filed online at many Federal Depository Libraries.
V. 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. In
addition, this action does not impose any enforceable duty or contain
any unfunded mandate as described in the Unfunded Mandates Reform Act
of 1995 (Pub. L. 104-4), or require prior consultation with State
officials as specified by Executive Order 12875 (58 FR 58093, October
28, 1993), or special considerations as required by Executive Order
12898 (59 FR 7629, February 16, 1994).
Because tolerances established on the basis of a petition under
section 408(d) of FFDCA do not require issuance of a proposed rule, the
regulatory flexibility analysis requirements of the Regulatory
Flexibility Act (RFA), 5 U.S.C. 604(a), do not apply. Prior to the
recent amendment of the FFDCA, EPA had treated such rulemakings as
subject to the RFA; however, the amendments to the FFDCA clarify that
no proposal is required for such rulemakings and hence that the RFA is
inapplicable. Nonetheless, the Agency has previously assessed whether
establishing tolerances or exemptions from tolerance, raising tolerance
levels, or expanding exemptions adversely impact small entities and
concluded, as a generic matter, that there is no adverse impact. (46 FR
24950, May 4, 1981).
Under 5 U.S.C. 801(a)(1)(A) of 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).
List of Subjects in 40 CFR Part 180
Environmental protection, Administrative practice and procedure,
Agricultural commodities, Pesticides and pests, Reporting and
recordkeeping requirements.
Dated: April 30, 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 for part 180 continues to read as follows:
Authority: 21 U.S.C. 346a and 371.
2. Section 180.436 is amended by revising the introductory text to
paragraph (a), by revising the column headings to the table in
paragraph (a), and by alphabetically adding entries for citrus crop
group; citrus oil; and citrus dried pulp.
Sec. 180.436 Cyfluthrin; tolerances for residues.
(a) General. Tolerances are established for residues of the
insecticide cyfluthrin (cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-
dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate; CAS Reg. No.
68359-37-5) in or on the following raw agricultural commodities:
------------------------------------------------------------------------
Parts per Expiration/ Revocation
Commodity million date
------------------------------------------------------------------------
* * * * *
Citrus crop group................... 0.2 Nov. 15, 1997
[[Page 25524]]
Citrus dried pulp................... 0.3 Do.
Citrus oil.......................... 0.3 Do.
* * * * *
------------------------------------------------------------------------
* * * * *
[FR Doc. 97-12195 Filed 5-8-97; 8:45 am]
BILLING CODE 6560-50-F