 

<EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE
PETITIONS PUBLISHED IN THE FEDERAL REGISTER  (1/1/2007)>

<EPA Registration Division contact: Joanne Miller Product Manager 21
(703) 305-6224 >

 

<INSTRUCTIONS:  Please utilize this outline in preparing the pesticide
petition.  In cases where the outline element does not apply, please
insert “NA-Remove” and maintain the outline. Please do not change
the margins, font, or format in your pesticide petition. Simply replace
the instructions that appear in green and brackets, i.e., “[insert
company name],” with the information specific to your action.>

<TEMPLATE:>

<[Nichino America, Inc.]>

<[Pesticide Petition No. 7F7190]>

<	EPA has received a pesticide petition (PP # 7F7190) from Nichino
America, Inc. 4550 New Linden Hill Road Suite 501 Wilmington, DE 19808
proposing, pursuant to section 408(d) of the Federal Food, Drug, and
Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180.585>

<>

<	1. by establishing a tolerance for residues of pyraflufen-ethyl for
combined residues of the herbicide, pyraflufen-ethyl (ethyl
2-chloro-5-(4-chloro-5-difluoromethoxy-(1-methyl-1H-pyrazol-3-yl)-4-fluo
rophenoxyacetate) and its acid metabolite, E-1
(2-chloro-5-(4-chloro-5-difluoromethoxy-(1-methyl-1H-pyrazol-3-yl)-4-flu
orophenoxyacetic acid), expressed in terms of the parent, in or on the
following raw agricultural commodities: soybeans: beans, forage at 0.05
parts per million (ppm), beans hay; at 0.1 parts per million (ppm). Also
grass forage, Crop Group 17 at 1.0 parts per million (ppm) and grass,
hay, crop group 17 at 1.2 parts per million (ppm).  

>

<	2. to establish an exemption from the requirement of a tolerance for
“NA-Remove”>

<EPA has determined that the petition contains data or information
regarding the elements set forth in section 408 (d)(2) of  FDDCA;
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.>

<A. Residue Chemistry>

<	1. Plant metabolism. The qualitative nature of the residues of 

pyraflufen-ethyl (ET-751) in corn, soybeans, and wheat and pasture grass
is adequately understood. The metabolism of pyraflufen-ethyl has been
studied in cotton, wheat, and potato. Metabolism in the plant involves
ester hydrolysis, de-methylation on the pyrazole ring and further
degradation of the phenoyxyacetate moiety to bound polar metabolites.
The nature of the residue is adequately understood and the residues of
concern are the parent, pyraflufen-ethyl, and the acid metabolite, E-1,
only.

>

<2. Analytical method. Aqueous organic solvent extraction, column clean
up, and quantitation by gas chromatography is used to measure and
evaluate the chemical residues.

>

<	3. Magnitude of residues. Several residue trials were conducted in
corn, soybeans, wheat, and pasture grass to satisfy the required EPA
region locations.   Based on these data, it is proposed that the Agency
retain established tolerances (40 CFR §180.585) for pyraflufen-ethyl
(ET-751) and its acid metabolite (E-1) for corn, grain, corn, stover,
corn, forage at 0.01 ppm; soybean seed and soybean forage at 0.01 ppm,
and wheat forage and hay at 0.1 ppm, wheat grain and wheat straw at 0.01
ppm and establish new tolerances in soybean hay at 0.1 ppm, pasture
grass forage at 1.0 ppm and pasture grass hay at 1.2 ppm.

>

    	4. Magnitude of the residue in animals.--i. Ruminants. The results
of the meat and milk 28-day feeding study conclude that no finite
residues of the parent, ET-751 or the metabolite E-15 can be detected in
milk at a dose level of 10 ppm, and that no residues of either ET-751 or
the acid metabolite, E-1, are detected in muscle, liver or fat tissues,
and low level residues of 0.0336 ppm in kidney tissues.  These results
concur with those of an earlier ruminant metabolism study (MRID
45283005) at a dose of 10 ppm. Since the results of this livestock
feeding study indicates that no finite residues could be detected in
meat and milk commodities from the anticipated dietary burdens based on
crop residue data, no tolerances for livestock commodities meat and milk
are proposed in this petition.

    ii. Poultry. The maximum poultry dietary burden results from a diet 

comprised of cotton meal, corn grain, corn milled byproducts, soybean
seed, soybean meal, soybean hulls, wheat grain, and wheat milled
byproducts for a total dietary burden that is significantly lower than
the levels that would require the proposal of tolerances in poultry.
This conclusion is based on the exaggerated rate metabolism studies
carried out on pyraflufen-ethyl and its acid metabolite. Therefore, an
exemption from tolerances in poultry meat, meat byproducts, fat, and 

eggs under 40 CFR 180.6(a)(3) and (b) is proposed as it is not possible
to establish with certainty whether finite residues will be incurred,
but there is no reasonable expectation of finite residues.

<B. Toxicological Profile>

<	1. Acute toxicity.  [Insert text.] “NA-Remove”>

<	2. Genotoxicty. [Insert text.] “NA-Remove”>

<	3. Reproductive and developmental toxicity. [Insert text.]
“NA-Remove”>

<	4. Subchronic toxicity. [Insert text.] “NA-Remove”

>

<	5. Chronic toxicity. [Insert text.] “NA-Remove”

	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 pyraflufen-ethyl as well as the no observed adverse effect level
(NOAEL) and the lowest 

observed adverse effect level (LOAEL) from the toxicity studies reviewed
are discussed in the Federal Register of April 30, 2003 (  HYPERLINK
"http://www.epa.gov/EPA-PEST/2003/April/Day-30/p10264.htm"  68 FR 23046
) (FRL-7300-9).

>

<	6. Animal metabolism.  The qualitative nature of the residues of
pyraflufen-ethyl and its acid metabolite, E-1, in animals is adequately
understood. Pyraflufen-ethyl is rapidly absorbed, metabolized, and
excreted to feces and urine, with greater than 90% of the administered
dose excreted within 24 hours in rats. Based on metabolism studies with
goats, hens, and rats, there is no reasonable expectation that
measurable pyraflufen-ethyl-related residues will occur in meat, milk,
poultry, or eggs from the proposed use.

>

<	7. Metabolite toxicology. No toxicologically significant metabolites
were detected in plant or animal metabolism studies for cotton or
potatoes.

>

<	8. Endocrine disruption. Chronic, lifespan, and multigenerational 

bioassays in mammals and acute and subchronic studies on aquatic
organisms and wildlife did not reveal any endocrine effects for
pyraflufen-ethyl. Any endocrine related effects would have been detected
in this comprehensive series of required tests. The probability of any
such effect due to agricultural uses of pyraflufen-

ethyl is negligible.

>

<C. Aggregate Exposure>

<	1. Dietary exposure. Acute dietary risk assessments are performed for
a food-use pesticide, if toxicological study has indicated the
possibility of an effect of concern occurring as a result of a one-day
or single exposure.  No adverse effect attributable to a single exposure
(dose) was observed in oral toxicity studies, including the
developmental toxicity studies in rats and rabbits.  Therefore, EPA did
not identify an acute dietary endpoint and an acute dietary assessment
was not performed.  Chronic dietary risk analyses was conducted to
estimate potential pyraflufen-ethyl residues in/on the following crops: 
corn, soybeans, wheat, and pasture grass using Dietary Exposure
Evaluation Model Software with the Food Commodity Intake Database
(DEEM-FCID).  These estimates assume that 100% of the crops contained
pyraflufen-ethyl and tolerance-level residues for pyroflufen-ethyl on
all treated crops.   Exposure estimates to water were based on modeling
with FIRST and SCI-GROW.

>

<	i. Food. The chronic population adjusted dose (cPAD) for the 

general population, based on residues at the tolerance levels and 100% 

of corn, soybeans, potato, wheat, and cotton crops treated was
calculated by the EPA in the Federal Register of  May 12, 2004 (69 FR
26305) (FRL-7358-2).  EPA has projected that exposure to
pyraflufen-ethyl from food will utilize <1% of the cPAD of 0.2 mg/kg/day
for the U.S. population and <1% of cPAD for children (1-6 years). 

>

<	ii. Drinking water. The residue of concern in drinking water was
determined to be pyraflufen-ethyl.  Based on the FIRST and SCI-GROW
models, the EECs of pyraflufen-ethyl for acute exposures are estimated
to be 1.25 parts per billion (ppb) for surface water and 0.002 ppb for
ground water. The EECs for chronic exposures are estimated to be 0.28
ppb for surface water and 0.002 ppb for ground water.

	2. Non-dietary exposure. EPA calculated the non-dietary exposure
scenarios in the Federal Register May 12, 2004 (69 FR 26305)
(FRL-7358-2). Pyraflufen-ethyl is registered in several non-food sites,
including airports, commercial plants, nurseries and ornamental
plantings; established ornamental turf; railroad, roadside, and utility
rights-of-ways, and other similar non-crop areas. 

>

<>

<D. Cumulative Effects>

<	Pyraflufen-ethyl belongs to the protox inhibitor class of 

compounds, and chemically is a 3-phenylpyrazole. The herbicidal 

activity of protox inhibitors is due to the inhibition of
protoporphyrinogen IX oxidase. All relevant toxicological data has been
provided to EPA. Chemicals with a similar mode of action, i.e., the
protox inhibitors, have different chemical structures compared to
pyraflufen-ethyl. Although other protox inhibitors have a similar
herbicidal mode of action, there is no information available to suggest
that these compounds exhibit a similar toxicity profile in the mammalian
system. We are aware of no information to indicate or suggest that
pyraflufen-ethyl has any toxic effects on mammals that would be
cumulative with those of any other chemical. Since pyraflufen-ethyl is
relatively non-toxic, cumulative effects of residues and other compounds
are not anticipated. Therefore, for the purposes of this Food Quality
Protection Act (FQPA) document, there should be no consideration of
cumulative risk that would require assessment.

>

<E. Safety Determination>

<U.S. population. 

i.  Acute risk. No adverse effect attributable to a single exposure
(dose) of pyraflufen-ethyl was observed in the oral toxicity studies,
including the developmental toxicity studies in rats and rabbits.
Therefore, an acute reference dose was not established and no acute risk
is expected.

ii. Chronic Risk.  Based on the chronic toxicity data, the cPAD for
pyraflufen-ethyl is considered to be 0.172 mg/kg/day. This value is
based on the NOAEL of 17.2 mg/kg/day observed in the chronic rat feeding
study and a safety (uncertainty) factor of 100, the worse case estimate
of chronic dietary exposure of pyraflufen-ethyl from cotton, potatoes,
corn, soybean, and wheat will utilize less than 1% of the cPAD for the
general U.S. population. 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. The complete and reliable toxicity
data and the conservative chronic exposure assumptions support the
conclusion that there is a reasonable certainty of no harm from dietary
(food) exposure to pyraflufen-ethyl and the acid metabolite residues.
Moreover, as exposure to residues of pyraflufen-ethyl and the acid
metabolite via water is negligible, there is a reasonable certainty of
no harm from aggregate exposure to pyraflufen-ethyl and the acid
metabolite residues.

iii.  Cancer Risk.  Cancer risk was calculated by the EPA in the Federal
Register May 12, 2004 (69 FR 26305) (FRL-7358-2) for both food and
water.  This assessment substantially overstates risk because it is
based on the assumption that all commodities covered by pyraflufen-ethyl
tolerances contain tolerance level residues.  The cancer risk estimate
was in the range of 1 in 1 million and does not exceed the Agency’s
level of concern for exposure from either food or water sources.  

>

<	2. Infants and children. The chronic dietary exposure of
pyraflufen-ethyl and the acid metabolite from corn, soybeans, and wheat
will utilize < 1% of the cPAD for children (1-6 years). Exposure to
potential residues in drinking water is expected to be negligible.  In
the Federal Register May 12, 2004 (69 FR 26305) (FRL-7358-2) after
calculating DWLOCs and comparing them to the EECs for surface and ground
water, EPA does not expect the aggregate exposure to children to exceed
the Agency’s level of concern.>

There is no evidence of increased susceptibility of rat or rabbit
fetuses following in utero exposure in the developmental studies with
pyraflufen-ethyl.  There is no evidence of increased susceptibility of
young rats n the reproduction study with Pyraflufen-ethyl.  EPA
concluded there are no residual uncertainties for pre- and/or post-natal
exposure.

<F. International Tolerances>

<	There are no Codex maximum residue level established for residues of
pyraflufen-ethyl and the acid metabolite, E-1, expressed in terms of
parent on any crops.

>

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