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Fenpropathrin - Pesticide Petition Filing 12/99

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[Federal Register: December 3, 1999 (Volume 64, Number 232)]
[Notices]
[Page 67905-67912]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr03de99-87]
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ENVIRONMENTAL PROTECTION AGENCY
[PF-900; FRL-6392-6]
Notice of Filing Pesticide Petitions To Establish a Tolerance for
Certain Pesticide Chemicals in or on Food
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice announces the initial filing of pesticide
petitions proposing the establishment of regulations for residues of
certain pesticide chemicals in or on various food commodities.

DATES: Comments, identified by docket control number PF-900, must be
received on or before January 3, 2000.

ADDRESSES: Comments may be submitted by mail, electronically, or in
person. Please follow the detailed instructions for each method as
provided in Unit I.C. of the "SUPPLEMENTARY INFORMATION" section. To
ensure proper receipt by EPA, it is imperative that you identify docket
control number PF-900 in the subject line on the first page of your
response.

FOR FURTHER INFORMATION CONTACT:  By mail: Shaja Brothers, Registration
Support Branch, Registration Division (7505C), Office of Pesticide
Programs, Environmental Protection Agency, 401 M St., SW., Washington,
DC 20460; telephone number: (703) 308-3194; and e-mail address:
brothers.shaja@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does This Action Apply to Me?

    You may be affected by this action if you are an agricultural
producer, food manufacturer or pesticide manufacturer. Potentially
affected categories and entities may include, but are not limited to:

------------------------------------------------------------------------
                                                          Examples of
           Categories                    NAICS            potentially
                                                       affected entities
------------------------------------------------------------------------
Industry                          111                 Crop production
                                  112                 Animal production
                                  311                 Food manufacturing
                                  32532               Pesticide
                                                       manufacturing
------------------------------------------------------------------------

    This listing is not intended to be exhaustive, but rather provides
a guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected. The North American Industrial Classification System (NAICS)
codes have been provided to assist you and others in determining
whether or not this action might apply to certain entities. If you have
questions regarding the applicability of this action to a particular
entity, consult the person listed in the "FOR FURTHER INFORMATION
CONTACT" section.

B. How Can I Get Additional Information, Including Copies of This
Document and Other Related Documents?

    1. Electronically. You may obtain electronic copies of this
document, and certain other related documents that might be available
electronically, from the EPA Internet Home Page at http://www.epa.gov/.
To access this document, on the Home Page select "Laws and
Regulations" and then look up the entry for this document under the
"Federal Register--Environmental Documents." You can also go directly
to the Federal Register listings at http://www.epa.gov/fedrgstr/.
    2. In person. The Agency has established an official record for
this action under docket control number PF-900. The official record
consists of the documents specifically referenced in this action, any
public comments received during an applicable comment period, and other
information related to this action, including any information claimed
as confidential business information (CBI). This official record

[[Page 67906]]

includes the documents that are physically located in the docket, as
well as the documents that are referenced in those documents. The
public version of the official record does not include any information
claimed as CBI. The public version of the official record, which
includes printed, paper versions of any electronic comments submitted
during an applicable comment period, is available for inspection in the
Public Information and Records Integrity Branch (PIRIB), Rm. 119,
Crystal Mall #2, 1921 Jefferson Davis Highway, Arlington, VA, from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.

C. How and to Whom Do I Submit Comments?

    You may submit comments through the mail, in person, or
electronically. To ensure proper receipt by EPA, it is imperative that
you identify docket control number PF-900 in the subject line on the
first page of your response.
    1. By mail. Submit your comments to: Public Information and Records
Integrity Branch (PIRIB), Information Resources and Services Division
(7502C), Office of Pesticide Programs (OPP), Environmental Protection
Agency, 401 M St., SW., Washington, DC 20460.
    2. In person or by courier. Deliver your comments to: Public
Information and Records Integrity Branch (PIRIB), Information Resources
and Services Division (7502C), Office of Pesticide Programs (OPP),
Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1921
Jefferson Davis Highway, Arlington, VA. The PIRIB is open from 8:30
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The
PIRIB telephone number is (703) 305-5805.
    3. Electronically. You may submit your comments electronically by
E-mail to: "opp-docket@epa.gov," or you can submit a computer disk as
described above. Do not submit any information electronically that you
consider to be CBI. Avoid the use of special characters and any form of
encryption. Electronic submissions will be accepted in Wordperfect 6.1/
8.0 or ASCII file format. All comments in electronic form must be
identified by docket control number PF-900. Electronic comments may
also be filed online at many Federal Depository Libraries.

D. How Should I Handle CBI That I Want To Submit to the Agency?

    Do not submit any information electronically that you consider to
be CBI. You may claim information that you submit to EPA in response to
this document as CBI 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. In addition to one complete
version of the comment that includes any information claimed as CBI, a
copy of the comment that does not contain the information claimed as
CBI must be submitted for inclusion in the public version of the
official record. Information not marked confidential will be included
in the public version of the official record without prior notice. If
you have any questions about CBI or the procedures for claiming CBI,
please consult the person identified in the "FOR FURTHER INFORMATION
CONTACT" section.

E. What Should I Consider as I Prepare My Comments for EPA?

    You may find the following suggestions helpful for preparing your
comments:
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide copies of any technical information and/or data you used
that support your views.
    4. If you estimate potential burden or costs, explain how you
arrived at the estimate that you provide.
    5. Provide specific examples to illustrate your concerns.
    6. Make sure to submit your comments by the deadline in this
notice.
    7. To ensure proper receipt by EPA, be sure to identify the docket
control number assigned to this action in the subject line on the first
page of your response. You may also provide the name, date, and Federal
Register citation.

II. What Action is the Agency Taking?

     EPA has received pesticide petitions as follows proposing the
establishment and/or amendment of regulations for residues of certain
pesticide chemicals in or on various food commodities under section 408
of the Federal Food, Drug, and Comestic Act (FFDCA), 21 U.S.C. 346a.
EPA has determined that these petitions contain data or information
regarding the elements set forth in section 408(d)(2); however, EPA has
not fully evaluated the sufficiency of the submitted data at this time
or whether the data supports granting of the petitions. Additional data
may be needed before EPA rules on the petitions.

List of Subjects

    Environmental protection, Agricultural commodities, Feed additives,
Food additives, Pesticides and pests, Reporting and recordkeeping
requirements.

    Dated: November 29, 1999.

James Jones,

Director, Registration Division, Office of Pesticide Programs.

Summaries of Petitions

    The petitioner summaries of pesticide petitions are printed below
as required by section 408(d)(3) of the FFDCA. The summaries of
petitions was prepared by the petitioner and represents the views of
the petitioner. EPA is publishing the petition summaries verbatim
without editing them in any way. The petition summary announces the
availability of a description of the analytical methods available to
EPA for the detection and measurement of the pesticide chemical
residues or an explanation of why no such method is needed.

2. Interregional Research Project Number 4

PP 9E6042

    EPA has received a pesticide petition (9E6042) from the
Interregional Research Project Number 4 (IR-4), Center for Minor Crop
Pest Management, at the Technology Centre of New Jersey, 681 U.S.
Highway #1, South, North Brunswick, NJ 08902-3390 proposing, pursuant
to section 408(d) of the FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part
180 by establishing a tolerances for residues of fenpropathrin, alpha-
cyano-3-phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate, in or
on the food commodities cucurbit vegetables (Crop Group 9) commodities
at 0.5 ppm. EPA has determined that the petition contains data or
information regarding the elements set forth in section 408(d)(2) of
the FFDCA; however, EPA has not fully evaluated the sufficiency of the
submitted data at this time or whether the data supports granting of
the petition. Additional data may be needed before EPA rules on the
petition. This notice includes a summary of the petition prepared by
Valent USA Corporation, the registrant, P.O. Box 8025, Walnut Creek, CA
94596-8025.

A. Residue Chemistry

    1. Plant metabolism. The plant metabolism of fenpropathrin has been
studied in five different crops: cotton, apple, tomato, cabbage, and
bean. Fenpropathrin, a cyanohydrin ester, has been labeled with
radiocarbon in three positions -- cyclopropyl ring, aryl rings, and
nitrile. The permutations of plant species and radiocarbon label
position yield a total of 17 separate, reviewed studies. Each of the
studies involved foliar treatment of the plants under either greenhouse
or field conditions and, while the actual treatment conditions and
times to harvest and analyses varied from study to study, the results
of the many studies are consistent. The total toxic residue is best
defined as parent, fenpropathrin.
    Fenpropathrin remains associated with the site of application and
only traces are found in seeds (e.g., bean or cotton) or in other parts
of the plant not directly exposed to the application. Much of the
parent residue can be removed from the plant material with a mild
hexane/acetone or hexane rinse, demonstrating that the residue is
located on or near the outside surface of the plant material. The
primary metabolic pathway for fenpropathrin in plants is similar to
that in mammals. There are no qualitatively unique plant metabolites;
the primary aglycones are identical in both plants and animals.
    2. Analytical method. Adequate analytical methodology is available
to detect and quantify fenpropathrin (and its metabolites) at residue
levels in numerous matrices. The methods use solvent extraction and
partition and/or column chromatography clean-up steps, followed by
separation and quantitation using capillary column gas-liquid
chromatography with flame ionization detection. The extraction
efficiency has been validated using radiocarbon samples from the plant
and animal metabolism studies. The enforcement methods have been
validated at independent laboratories and by EPA. The limit of
quantitation (LOQ) for fenpropathrin is 0.01 ppm.
    3. Magnitude of residues. The field residue data to support the
proposed fenpropathrin tolerance on the cucurbit vegetables crop
grouping includes data on melons (cantaloupe) from 10 sites, cucumbers
from 8 sites and summer squash from 7 sites providing data from 25
sites across the United States. Exaggerated rate and residue decline
studies were included. In the samples that fit the proposed use pattern
the average residue is 0.078 ppm with a maximum value of 0.31 ppm.
Samples with measured residue values below the 0.01 ppm LOQ were
assumed, for the purposes of calculation, to contain residue values of
0.005 ppm (1/2 the LOQ).

[[Page 67910]]

B. Toxicological Profile

    1. Acute toxicity. Acute toxicity studies with technical
fenpropathrin: Oral lethal dose (LD)50 in the rat is 54.0
mg/kg for males and 48.5 mg/kg for females - Toxicity Category I;
dermal LD50 is 1,600 mg/kg for males and 870 mg/kg for
females - Category II; acute inhalation (impossible to generate
sufficient test article vapor or aerosol to elicit toxicity) - Category
IV; primary eye irritation (no corneal involvement, mild iris and
conjunctival irritation) - Category III; and primary dermal irritation
(no irritation) - Category IV. Fenpropathrin is not a sensitizer.
    2. Genotoxicty. An Ames Assay was negative for Salmonella TA98,
TA100, TA1535, TA1537, and TA1538; and E. coli WP2uvrA (trp-) with or
without metabolic activation. Sister Chromosome Exchange in Chinese
hamster ovary (CHO) cells there were no increases in sister chromatid
exchanges seen. Cytogenetics in vitro - negative for chromosome
aberrations in CHO cells exposed in vitro to toxic doses (≥
30 μg/ml) without activation; and to limit of solubility (1,000
μg/ml) with activation. In Vitro Assay in Mammalian Cells -
equivocal results - of no concern. DNA Damage/Repair in Bacillus
subtilis - not mutagenic or showing evidence of DNA damage at
≥ 5,000 μg/paper disk.
    3. Reproductive and developmental toxicity. A 3-generation
reproduction study was performed with rats dosed with fenpropathrin at
concentrations of 0, 40, 120, or 360 ppm (0, 3.0, 8.9, or 26.9 mg/kg/
day in males; 0, 3.4, 10.1, or 32.0 mg/kg/day in females,
respectively). The parentals (male/female) systemic NOAEL is 40 ppm
(3.0/3.4 mg/kg/day). The systemic LOAEL is 120 ppm (8.9/10.1 mg/kg/day)
based on body tremors with spasmodic muscle twitches, increased
sensitivity and maternal lethality. The reproductive NOAEL is 120 ppm
(8.9/10.1 mg/kg/day), and the reproductive LOAEL is 360 ppm (26.9/32.0
mg/kg/day) based on decrease mean F1B pup weight, increased
F2B loss. The pups (male/female) developmental NOAEL is 40
ppm (3.0/3.4 mg/kg/day), and the developmental LOAEL is 120 ppm (8.9/
10.1 mg/kg/day) based on body tremors, increased mortality.
    In a developmental toxicity study in rats, pregnant female rats
were dosed by gavage on gestation days 6 through 15 at 0 (corn oil
control) 0.4, 1.5, 2.0, 3.0, 6.0, or 10.0 mg/kg/day. The maternal NOAEL
is 6 mg/kg/day and the LOAEL is 10 mg/kg/day based on death,
moribundity, ataxia, sensitivity to external stimuli, spastic jumping,
tremors, prostration, convulsions, hunched posture, squinted eyes,
chromodacryorrhea, and lacrimation. The developmental NOAEL is > 10 mg/
kg/day.
    In a developmental toxicity study in rabbits, pregnant female New
Zealand rabbits were dosed by gavage on gestation days 7 through 19 at
0, 4, 12, or 36 mg/kg/day. Maternal NOAEL is 4 mg/kg/day and the
maternal LOAEL is 12 mg/kg/day based on grooming, anorexia, flicking of
the forepaws. The developmental NOAEL is > 36 mg/kg/day highest dose
tested (HDT).
    4. Subchronic toxicity. In a subchronic oral toxicity study, rats
were dosed at concentrations of 0, 3, 30, 100, 300, or 600 ppm in the
diet. The LOAEL is 600 ppm (30 mg/kg/day) based on body weight
reduction (female), body tremors, and increased brain (female) and
kidney (male) weights. The NOAEL is 300 ppm (15 mg/kg/day).
    5. Chronic toxicity. In a chronic feeding/carcinogenicity study,
rats were dosed at 0, 50, 150, 450, or 600 ppm in the diet (0, 1.93,
5.71, 17.06, or 22.80 mg/kg/day in males, and 0, 2.43, 7.23, 19.45, or
23.98 mg/kg/day in females). There was no evidence of carcinogenicity
at any dose up to and including 600 ppm. The systemic NOAEL (male) is
450 ppm (17.06 mg/kg/day). The systemic NOAEL (female) is 150 ppm (7.23
mg/kg/day), and the systemic LOAEL (male) is 600 ppm based on increased
mortality, body tremors, increased pituitary, kidney, and adrenal
weights. The systemic LOAEL (female) is 450 ppm (19.45 mg/kg/day) based
on increased mortality and body tremors.
    In a chronic feeding/carcinogenicity study, mice were fed diets
containing 0, 40, 150, or 600 ppm (0, 3.9, 13.7, or 56.0 mg/kg/day in
males, and 0, 4.2, 16.2, or 65.2 mg/kg/day in females). Mortality was
highest during the final quarter of the study, but the incidence was
similar in all dosed and control groups. No other indications of
toxicity or carcinogenicity were seen. The systemic NOAEL is > 600 ppm
(HDT; male/female, 56.0/65.2 mg/kg/day).
    6. Animal metabolism. In a metabolism study in rats, animals were
dosed with fenpropathrin radiolabelled in either the alcohol or acid
portion of the molecule. Rats received 14 daily oral low-doses of 2.5
mg/kg/day of unlabelled fenpropathrin followed by a 15th dose of either
the alcohol or acid radiolabelled fenpropathrin. Groups of rats
received a single dose of either of the two radiolabelled test articles
at 2.5 mg/kg or 25 mg/kg. The major biotransformations included
oxidation at the methyl group of the acid moiety, hydroxylation at the
4'-position of the alcohol moiety, cleavage of the ester linkage, and
conjugation with sulfuric acid or glucuronic acid. Four metabolites
were found in the urine of rats dosed with alcohol labeled
fenpropathrin. The major metabolites were the sulfate conjugate of 3-
(4'-hydroxyphenoxy)benzoic acid and 3-phenoxybenzoic acid (22-44% and
3-9% of the administered dose, respectively). The major urinary
metabolites of the acid-labeled fenpropathrin were TMPA-glucuronic acid
and TMPA-CH2OH (11-26% and 6-10% of the administered dose,
respectively). None of the parent chemical was found in urine. The
major elimination products in the feces included the parent chemical
(13-34% of the administered dose) and four metabolites. The fecal
metabolites (and the percentage of administered dose) included
CH2OH-fenpropathrin (9-20%), 4'-OH-fenpropathrin (4-11%),
COOH-fenpropathrin (2-7%), and 4'-OH-CH2OH-fenpropathrin (2-
7%). There are no qualitatively unique plant metabolites. The primary
aglycones are identical in both plants and animals; the only difference
is in the nature of the conjugating moieties employed.
    7. Metabolite toxicology. The metabolism and potential toxicity of
the small amounts of terminal plant metabolites have been tested on
mammals. Glucoside conjugates of 3-phenoxy-benzyl alcohol and 3-
phenoxybenzoic acid, administered orally to rats, were absorbed as the
corresponding aglycones following cleavage of the glycoside linkage in
the gut. The free or reconjugated aglycones were rapidly and completely
eliminated by normal metabolic pathways. The glucose conjugates of 3-
phenoxybenzyl alcohol and 3-phenoxy-benzoic acid are less toxic to mice
than the corresponding aglycones.
    8. Endocrine disruption. No special studies to investigate the
potential for estrogenic or other endocrine effects of fenpropathrin
have been performed. However, as summarized above, a large and detailed
toxicology data base exists for the compound in all required
categories. These studies include evaluations of reproduction and
reproductive toxicity and detailed pathology and histology of endocrine
organs following repeated or long-term exposure. According to the
registrant, these studies are considered capable of revealing endocrine
effects and no such effects were observed.

C. Aggregate Exposure

    1. Dietary exposure. The chronic population adjusted dose (cPAD) is
established at 0.025 mg/kg/day. The acute population adjusted dose
(aPAD)

[[Page 67911]]

is established at 6.0 mg/kg/day (systemic). Thus, both chronic and
acute dietary exposure and risk analyses are necessary.
    Chronic and acute dietary exposure analyses were performed for
fenpropathrin using anticipated residues and accounting for proportion
of the crop treated. The crops included in the analyses are the
cottonseed, currants, peanuts, strawberries, soybeans and grapes, and
the crop groupings head and stem brassica, fruiting vegetables,
cucurbit vegetables, citrus fruits, and pome fruits; processed products
from these crops; and the resulting secondary residues in meat, milk,
and eggs. Currants and soybeans (and soybean products) were entered
into the analyses using tolerance-level residues and 100% or 1% of the
crop treated, respectively. The fruiting vegetables (Crop Group 9), was
substituted for tomatoes in the dietary exposure and risk analyses. IR-
4 is presently working on this use expansion, and a tolerance petition
adding fruiting vegetables and using these same dietary exposure
analyses will be forthcoming. The various proportion of crop treated
values were derived from published marketing data for crops for which
there are existing fenpropathrin uses, and extrapolated from the uses
of other pyrethroid insecticides for pending crops. Proportion of crop
treated was assumed to be equal for all crops in a crop grouping. A
report of these exposure/risk analyses has been submitted to the Agency
including a detailed description of the methodology and assumptions
used.
    i. Food. Chronic dietary exposure was at or below 2.7% of the cPAD
with apples and grapes the commodities contributing the most to chronic
exposure. The anticipated residue contribution (ARC) is estimated to be
0.000204 milligrams/kilograms/bodyweight/day (mg/kg/ bwt/day) and
utilize 0.8% of the cPAD for the overall U.S. population. The ARC for
childern 1-6 years old and childern 7-12 years old (subgroups most
highly exposed) are estimated to be 0.000678 mg/kg bwt/day and 0.000325
mg/kg bwt/day and utilizes 2.7 and 1.3% of the cPAD, respectively. The
ARC for females (13+/Nursing) 0.000248 mg/kg bwt/day and utilizes 1.0%
of the cPAD. The ARC for all infants (< 1-year old) and non-nursing
infants (<1-year old) is 0.000243 mg/kg bwt/day and 0.000284 mg/kg bwt/
day respectivley and utilizes 1.0% of the cPAD. The ARC for nursing
infants (< 1-year old) is 0.000103 and utilizes 0.4% of the cPAD.
Generally speaking, the registrant has no cause for concern if total
residue contribution for published and proposed tolerances is less than
100% of the cPAD.
    Acute dietary exposure was calculated at the 99.9th percentile of
exposure and margins of exposure (MOE) were calculated for the U.S.
population and the subpopulations with the highest risk, as follows:
U.S. population (MOE of 490), females (13+) (MOE 927), all infants (MOE
347), nursing infants (< 1) (MOE 384), non-nursing infants (MOE 328),
childern 1-6 years old (MOE 238), and childern 7-12 years old (MOE
410). In all cases, margins of exposure exceed one-hundred.
    ii. Drinking water. Since fenpropathrin is applied outdoors to
growing agricultural crops, the potential exists for fenpropathrin or
its metabolites to reach ground or surface water that may be used for
drinking water. Because of the physical properties of fenpropathrin,
the registrant has determined that it is unlikely that fenpropathrin or
its metabolites can leach to potable ground water.
    To further quantify potential exposure from drinking water, surface
water concentrations for fenpropathrin were estimated using genetic
expected environmental concentration (GENEEC) 1.2, and the most intense
field use scenario. The average 56-day concentration predicted in the
simulated pond water was 0.22 parts per billion (ppb). The residence
time of fenpropathrin in surface water has been measured and is short.
In pond studies, fenpropathrin half-life in the water column were less
than 1.5 days, thus this 56-day modeled half-lifes probably
considerably overestimates any real surface water concentration. Using
standard assumptions about body weight (bwt) and water consumption, the
chronic exposure from drinking water would be 6.3 x 10-6 and
2.2 x 10-5 mg/kg bwt/day for adults and children,
respectively; less than 0.09% of the cPAD for children. Based on this
worse case analysis, the contribution of water to the dietary risk is
negligible.
    2. Non-dietary exposure. Fenpropathrin, as the product TAME 2.4 EC
Spray, is a restricted use material and registered for professional
non-food use both indoors and outdoors on ornamentals and non-bearing
nursery fruit trees. Fenpropathrin has no animal health, homeowner,
turf, termite, indoor pest control, or industrial uses. Quantitative
information concerning human exposure from this ornamental use is not
available, but exposure to the general public from this use of
fenpropathrin is expected to be minimal. No endpoints of concern were
identified for occupational or residential, dermal or inhalation
exposures of any duration. Thus, no risk assessment is needed.

D. Cumulative Effects

    Section 408(b)(2)(D)(v) requires that the Agency must consider
"available information" concerning the cumulative effects of a
particular pesticide's residues and "other substances that have a
common mechanism of toxicity." Available information in this context
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.

E. Safety Determination

    1. U.S. population--i. Chronic risk--adults. Using the dietary
exposure assessment procedures described above for fenpropathrin,
calculated chronic dietary exposure resulting from residue exposure
from existing and proposed uses of fenpropathrin is minimal. The
estimated chronic dietary exposure from food for the overall U.S.
population is less than 1% of the cPAD. Addition of the small but worse
case potential chronic exposure from drinking water (calculated above,
6.3 x 10-6 mg/kg bwt/day) to the highest chronic exposure value from
food increases the maximum occupancy of the cPAD only slightly from
0.99% to 1.02%. Generally, the Agency has no cause for concern if total
residue contribution is less than 100% of the cPAD.
    ii. Acute Risk--adults. The potential acute exposure from food to
the U.S. population and various non-child/infant populations subgroups
(shown above) provide MOE values greatly exceeding 100. Addition of the
worse case, but very small "background" dietary exposure from water
is not sufficient to change the MOE values significantly. The
registrant concludes that there is a reasonable certainty that no harm
will result to the overall U.S. population from aggregate, acute
exposure to fenpropathrin residues.
    2. Infants and children--safety factor for infants and children. In
assessing the potential for additional sensitivity of

[[Page 67912]]

infants and children to residues of fenpropathrin, FFDCA section 408
provides that EPA shall apply an additional margin of safety, up to
ten-fold, for added protection for infants and children in the case of
threshold effects unless EPA determines that a different margin of
safety will be safe for infants and children.
    i. Chronic risk--infants and children. Using the dietary exposure
assessment procedures described above, calculated chronic dietary
exposure resulting from residue exposure from existing and proposed
uses of fenpropathrin is minimal. The estimated chronic dietary
exposure from food to infant and child subgroups ranges from 2.7%
[children (1-6 years), 0.000678 mg/kg bwt/day] to 0.4% [nursing infants
(< 1-year), 0.000103 mg/kg bwt/day] of the cPAD. Addition of the small
but worse case potential chronic exposure from drinking water
(calculated above, 2.2 x 10-5 mg/kg bwt/day) to the highest
chronic exposure value from food increases the maximum occupancy of the
cPAD only slightly from 2.7% to 2.8%. The registrant concludes that
there is a reasonable certainty that no harm will result to infant and
child subgroups of the U.S. population from aggregate, chronic exposure
to fenpropathrin residues.
    ii. Acute risk--infants and children. The potential acute exposure
from food to the various child and infant population subgroups all
provide MOE values exceeding 100. Addition of the worse-case, but very
small "background" dietary exposure from water (2.2 x 10-5
mg/kg bwt/day) is not sufficient to change the MOE values
significantly. The registrant concludes that there is a reasonable
certainty that no harm will result to infants and children from
aggregate, acute exposure to fenpropathrin residues.

 F. International Tolerances

    There are no Codex, Canadian, or Mexican residue limits for
residues of fenpropathrin in or on cucurbit vegetables (Crop Group 9).
[FR Doc. 99-31442 Filed 12-2-99; 8:45 am]
BILLING CODE 6560-50-F