Document ID: EPA-HQ-OPP-2008-0066-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-02-06T05:00Z

EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE
PETITIONS PUBLISHED IN THE FEDERAL REGISTER  (7/1/2007)

EPA Registration Division contact: [Ms. Kathryn Montague, 703-305-1243]

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, i.e., “[insert company
name],” with the information specific to your action.

TEMPLATE:

[Syngenta Crop Protection, Inc.]

[Insert petition number]

	EPA has received a pesticide petition ([insert petition number]) from
[Syngenta Crop Protection, Inc.], [P.O. Box 18300, Greensboro, NC 27419]
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.

(Options (pick one)

	1. by establishing a tolerance for residues of

	2. to establish an exemption from the requirement of a tolerance for

	[fluazifop-p-butyl] in or on the raw agricultural commodity [dry beans,
peanuts, soybean, soybean meal and soybean refined oil] at [25, 1.5,
2.5, 2.5 and 0.01 respectively] parts per million (ppm).  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 previously submitted plant metabolism of
fluazifop-p-butyl in plants has been reviewed by the United States
Environmental Protection Agency (EPA) Metabolism Assessment Review
Committee (MARC) and reported in the memorandum: Fluazifop-P-butyl.
Report of the Metabolism Assessment Review Committee (PC Code: 122809,
DP Barcode: 298939, July 8, 2004).  The aforementioned EPA review
concluded that the metabolism of fluazifop-p-butyl in plants is
understood for soybeans with the majority of the residue in soybeans
found to be fluazifop acid in free or conjugated forms.  Dry beans and
peanuts are members of the same scientific classification (Kingdom:
Plantae, Division: Magnoliophyta, Class: Magnoliopsida, Order: Fables,
Family: Fabaceae (also known as Leguminosae), Subfamily: Faboideae) as
soybeans and as such, the metabolism data for soybeans are expected to
be both relevant and analogous for the proposed new uses of
fluazifop-p-butyl.  EPA has concluded that fluazifop (free and
conjugated) and fluazifop acid (free and conjugated) are considered to
be the residues of concern for tolerance expression in plants.]

	2. Analytical method. [The analytical method utilized in the studies
supporting this action is based upon PAM Vol. II, Method II for the
enforcement of tolerances for fluazifop-p-butyl residues of concern for
oily and non-oily crops.  Using this method, residues of
fluazifop-p-butyl, fluazifop, and any ester or acid conjugates are
extracted from crop samples using a mixture of acetonitrile and dilute
acid.  Residues are then hydrolyzed using hydrochloric acid to fluazifop
and further cleaned up via solvent partitioning, and absorption
chromatography.  Once sufficiently cleaned up, the samples are
subsequently derivatized to form the methyl ester derivative of
fluazifop prior mass-selective detection using GC/MS.  It should be
noted that this analytical method does not distinguish the optical
isomers of fluazifop-butyl or fluazifop but instead, hydrolyzes these
residues to a common moiety (fluazifop acid) and as such, the detected
residues are reported as “fluazifop” residues.]

	3. Magnitude of residues. [Residue data was generated to establish
tolerances for the proposed new uses of fluazifop-p-butyl on dried beans
(subgroup 6-C) and peanuts.  These data were generated based upon the
proposed new use patterns which allows for two sequential applications
of 0.375 lb active ingredient per acre (lbs ai/A) applied at a 14 day
interval and harvest 60 days after last fluazifop-p-butyl application to
dry beans and 40 days following the last application of fluzifop-p-butyl
to peanuts.   

In addition to establishing tolerances for the aforementioned new crop
uses, this petition is also intended to modify the existing tolerances
on soybean in support of allowing post-bloom applications in addition to
the currently approved pre-bloom applications.  The proposed new
tolerance on soybean is 2.5 ppm based upon residue trials conducted in
2000 in which both pre- and post-bloom applications of fluazifop-p-butyl
were made to soybeans.  To evaluate the potential for concentration
during processing, an exaggerated rate processing study was conducted on
soybeans for the proposed new use pattern.  The residue levels
determined on the processed fractions demonstrated only slight
concentration in the meal (1.3X) and no concentration in either hulls
(0.78X) or oil (<0.01X).  Based upon the results of the exaggerated rate
processing study along with the actual field trial residue data, the
proposed tolerance for soybean meal is 2.5 ppm and 0.01 ppm for soybean
oil.  No tolerance is proposed for soybean hulls due to the labeled
prohibition against grazing or harvesting for forage and hay.

i. Dry Bean.  Twelve residue field trials were carried out during 2000
in 10 states throughout the United States (Syngenta Report Number
1431-01).  Two applications of fluazifop-p-butyl (as Fusilade® DX; EPA
Reg. No. 100-1070) were applied broadcast of the crop canopy at 0.375
lbs ai/A with an interval between sprays of 12-14 days for control of
annual and perennial grass weeds.  Control and duplicate treated dry
bean seed samples were harvested at normal harvest, 59-60 days following
the last fluazifop-p-butyl application.  Analyses of the samples
collected from these trials indicated that for the control (un-treated)
samples no residues were detected above the Limit of Quantitation (0.01
mg/kg) and the total detected fluazifop residues in the treated samples
ranged form 0.42 to 21 mg/kg (ppm).  The residue values generated in
these studies were input into the NAFTA Tolerance/MRL tool which
generated projected tolerances based upon the calculation method
utilized.  A 99th percentile tolerance of 55 ppm was indicated as
appropriate by the tool based upon the EU Method I Log Normal model. 
This value represents an overly conservative projection that is
approximately three times higher than the highest residue detected in
the field samples (21 ppm).  A more appropriate estimate of 25 ppm
determined using the EU Method I Normal is being proposed for this new
use pattern.  This value is consistent with the actual field trial data
also with the outputs of two other models: the Mean + 3SD method which
predicted a tolerance of 25 ppm and the UCL Median 95th method which
predicted 19 ppm. 

ii. Peanut.  Twelve residue field trials on peanut in 7 states were
carried out during 2000 (Syngenta Study Number 1435-01).  In these
studies, two applications of fluazifop-p-butyl (as Fusilade® DX) were
applied broadcast of the crop canopy at 0.375 lbs ai/A with a spray
interval of 12-14 days for control of annual and perennial grass weeds. 
One trial was lost due to an early freeze.  Control and duplicate
treated unshelled peanut samples were harvested (dug) at normal harvest,
38-40 days following the last application of fluazifop-p-butyl.  The
results of these trials indicated that no samples were found with
residues above the Limit of Quantitation (0.01 mg/kg) in the non-treated
(control samples) and for the treated samples the total fluazifop
residues ranged form 0.12 to 1.0 mg/kg.  The residue values generated in
these studies were input into the NAFTA Tolerance/MRL tool which
generated projected tolerances based upon the calculation method
utilized.  A 99th percentile tolerance of 1.5 ppm was indicated as
appropriate by the tool based upon the EU Method I Log Normal model.  

iii. Soybean.  Seventeen residue field trials on soybean in 12 states
were carried out during 2000 (Syngenta Study Number 1437-01).  In these
studies, two applications of fluazifop-p-butyl (as Fusilade® DX) were
applied broadcast over the crop canopy.  The first application was made
pre-bloom  at 0.375 lbs ai/A at the V5 stage followed by a post-bloom
application  of  0.094 lbs ai/A at the R3 stage.  Crop growth stage V5
was defined as plants with four nodes (counting the unifoliate node)
with fully developed trifoliate leaves.  No blooms are present at the V5
stage.  The R3 stage was defined as beginning of pod growth.  There is
at least on pod 5mm (3/16 inch) long at one of the four uppermost fully
developed leaf nodes on the main stem at the R3 stage.  Control and
duplicate soybean seed samples were taken for analysis at normal
maturity, 56 to 104 days following the last application of
fluazifop-p-butyl.  The results of these trials indicated that no
samples were found with residues above the LOQ (0.01 mg/kg) in the
non-treated (control samples) and for the treated samples the total
fluazifop residues ranged from 0.06 to 1.8 mg/kg.  The residue values
generated in these studies were input into the NAFTA Tolerance/MRL tool,
which generated projected tolerances based upon the calculation method
utilized.  A 99th percentile tolerance of 2.5 ppm was indicated as
appropriate by the tool based upon the Mean + 3SD model]

B. Toxicological Profile

	1. Acute toxicity.  [Fluazifop-p-butyl technical and the end-use
formulation have low acute toxicity by oral, dermal and inhalation
exposure routes. For fluazifop-p-butyl technical, the oral LD50 in rats
is 3680 mg/kg for males and 2451 mg/kg for females.  The rabbit dermal
toxicity LD50 is >2000 mg/kg and the rat inhalation LC50 is 1.7 mg/l
air. Fluazifop-p-butyl technical is mildly irritating to the rabbit eye
and slightly irritating to rabbit skin.  Fluazifop-p-butyl technical is
not a skin sensitizer.]

	2. Genotoxicty. [Fluazifop-p-butyl has been tested for its potential to
induce gene mutation and chromosomal changes in different test systems. 
Fluazifop-p-butyl was negative in bacterial reverse gene mutation assays
and in mouse lymphoma mammalian cell mutation assays.  Fluazifop-p-butyl
was negative in in vitro chromosomal aberrations essay in human blood
lymphocytes and was negative in the in vivo mouse micronucleus test.]

	3. Reproductive and developmental toxicity. [A number of rat
developmental toxicity studies have been conducted with
fluazifop-p-butyl.  Based on the HED review of all relevant
developmental toxicity studies with fluazifop-p-Butyl, the Agency
concluded “Though increased susceptibility of offspring was observed
in rats, the degree of concern is low.  The endpoint of concern (delayed
ossifications) is a well defined endpoint based on five developmental
toxicity studies and the NOAEL/LOAEL(s) are much lower dose levels than
resulted in the malformations.  A developmental endpoint of concern for
a single dose effect (diaphragmatic hernia) is used for assessing acute
dietary risk. Therefore, there is no residual uncertainty for pre and/or
post natal toxicity.”  The overall NOAEL for the rat studies is 2.0
mg/kg/day and the LOAEL is 5.0 mg/kg/day. For single dose effect, the
NOAEL is 50 mg/kg/day and the LOAEL is 200 mg/day based on the
diaphragmatic hernia malformations.

In the fluazifop-p-butyl developmental toxicity test in rabbits, the
maternal and developmental NOAEL is 10 mg/kg/day and the LOAEL is 50
mg/kg/day.  The maternal LOAEL is based on death, abortion and body
weight loss in dams, and the developmental LOAEL is based on increased
13th rib and increased incidence of delayed ossification of sternebrae 2
and 5. 

A rat reproduction toxicity study was conducted with fluazifop-butyl,
and it has been determined that studies on fluazifop-butyl may be used
to support fluazifop-p-butyl due to equivalency in toxicity.
(Fluazifop-p-butyl: Revised HED Chapter of the Tolerance Reassessment
Eligibility Document (TRED). PC Code 122809, Case # 2285, DP Barcode:
D316891).  Fluazifop-butyl was administered orally to groups of Wistar
male and female rats at dose levels of 0, 10, 80 and 250 ppm. Clinical
observations were unremarkable. Signs of systemic toxicity were seen in
organ weight changes in F1 adult males and females at the 250 ppm dose
level and less frequently at the 80 ppm dose level.  In F1 adult males
and females liver weights were significantly increased at 250 ppm,
kidney weights were increased in F1 adult females at the same dose, and
spleen weights in F1 males were decreased at 80 and 250 ppm. The number
of live F1 and F2 pups was significantly decreased at 250 ppm. F1 pup
weights were not affected at any dose level, but F2 pups showed reduced
weight at the highest dose level. Hydronephroses was increased in F1 and
F2 pups at 250 ppm. Decrease of testes and epididymal weight of the P0
and F1 adults were observed at the two highest dose levels. Slight
pathology was observed in the testes of the F1 adults at this dose
level. F1 adult females showed increased ovarian weight at 250 ppm.
Pituitary and uterine weights were reduced in adult F1 females at the
two highest doses. For parental systemic toxicity, the NOAEL is 0.74
mg/kg/day in males and 7.7 mg/kg/day in females. The LOAEL is 5.8
mg/kg/day in males based on decreased spleen weight and 21.7 mg/kg/day
in females based on the increase in absolute and relative liver and
kidney weights and geriatric necropathy. For offspring toxicity, the
NOAEL is 7.1 mg/kg/day and the LOAEL is 21.7 mg/kg/day based on
decreased viability of F1 and F2 pups and decreases in F2 pup weight.
The NOAEL for reproductive toxicity is 0.74 mg/kg/day in males and 0.88
mg/kg/day in females. The LOEAL is 5.8 mg/kg/day in males based on
decreases in absolute and relative testes and epididymal weights and 7.1
mg/kg/day in females based on decreases in absolute and relative
pituitary and uterine weights.]

	4. Subchronic toxicity. [Fluazifop-p-butyl was evaluated in a number of
subchronic studies.  In a 90 day rat oral toxicity study with
fluazifop-p-butyl, the NOAEL was 0.5 mg/kg/day.  Effects at higher doses
included decreased spleen and testicular weight and decreased
hematological parameters in males.  Fluazifop-p-butyl was also evaluated
in a 90 day oral toxicity study with hamsters. The NOAEL was 78.3
mg/kg/day, based on decreased body weight and body weight gain as well
as food efficiency in males at higher dose levels. Signs of liver
toxicity and centrilobular eosinophilia were observed in males and
females. No dermal toxicity study was conducted; however the study was
conducted with a similar compound, fluazifop-butyl.  In a 21/28 day
dermal rabbit study conducted with fluazifop-butyl, the NOAEL was 100
mg/kg/day. LOAEL was 500 mg/kg/day based on the death of a male.]

	5. Chronic toxicity. [Fluazifop-p-butyl was not carcinogenic in a
hamster carcinogenicity study. In this study, fluazifop-p-butyl was
administered to Golden Syrian hamsters at dose levels of 0, 0, 12.5,
47.4, and 193.6 mg/kg/day (males) and 0,0, 12.1, 45.5, and 181.4,
mg/kg/day (females) for 80 weeks. No changes in body weight or food
consumption were observed. No biologically significant changes in
hematology were seen. Brain liver and kidney weights were higher at the
highest dose level in both sexes. In males, testes weights were
decreased at 47.4 mg/kg/day and above. Histopathological examination
revealed evidence of toxicity in the testes, epididymis, prostate, eyes,
gall bladder in males and in the ovaries of females. No dose related
tumors were seen in males. In females, there was a slightly higher
incidence of benign tumors of the stromal cell/sex cord tissue of the
ovary which was statistically significant at the highest dose level when
compared to the combined control group. The combined incidence of benign
and malign tumors combined however, was not statistically significant at
any dose level. In conclusion, fluazifop-p-butyl is not oncogenic and
the NOAEL is 12.5 mg/kg/day for males and 12.1 mg/kg/day for females.

No rat carcinogenicity study or chronic dog study was conducted with
fluazifop-p-butyl, however the studies were conducted with a similar
compound, fluazifop-butyl.  In a combined carcinogenicity/chronic
toxicity study in Wistar rats, fluazifop-butyl was administered at dose
levels of 0, 0.1, 0.51, 4.15,and 12.29 mg/kg/day to males and 0, 0.127,
0.65, 5.20, 16.0 mg/kg/day to females. As stated in the EPA HED document
(204), “The LOAEL in males is 80 ppm (4.15 mg/kg/day) based on
increased mortality and nephropathy from start to week 52 of the study.
The NOAEL is 10 ppm (0.51 mg/kg/day in males). The LOAEL in females is
250 ppm (16.0 mg/kg/day) based on increased morality and nephropathy
during the first 52 weeks of the study and increased ovarian weight and
ovarian cysts at termination. The NOAEL was 80 ppm (5.2 mg/kg/day) for
females.”  At the doses tested, there was no treatment related
increase in tumor incidence when compared to controls.  In accordance
with the 1999 Draft Carcinogen Risk Assessment, Guideline (April, 1999),
EPA classified fluazifop-butyl and fluazifop-P-butyl as “Not likely to
be carcinogenic in humans,” based on the lack of evidence of
carcinogenicity in rats and hamsters.

In a 55 week chronic toxicity study with Beagle dogs, Fluazifop-butyl
was administered at dose levels of 0, 5, 25, and 125 mg/kg/day. Five out
of six males and two out of six females of the 125 mg/kg/day dose group
had to be euthanized. Organ weight was not affected and no lesions
attributable to the treatment were observed in the surviving dogs.
Increased incidence of adrenal cortical fatty vacuolation was seen in
the 25 and 125 mg/kg/day dose groups. Increased incidence of thymic
involution was seen in the 25mg/kg/day dose group. Toxic effects in the
highest dose group included eye, gastrointestinal tract lesions, adrenal
and bone marrow pathology, thymic involution and changes in hematology
and blood clinical chemistry. The LOAEL was 25 mg/kg/day, and the NOAEL
was 5 mg/kg/day.]

	6. Animal metabolism. [Fluazifop-butyl is a herbicide with mixed
isomeric [RS] content, while Fluazifop-p-butyl is the purified [R]
enantiomer.  Metabolism studies in rats show that both products are
rapidly hydrolyzed to fluazifop-acid.  Rat metabolism data showed that
R,S-fluazifop-butyl is converted to R-fluazifop acid within a short time
period. Fluazifop-butyl is rapidly hydrolyzed to fluazifop acid by blood
esterases and the S-enantiomer is rapidly converted to the R-enantiomer.
 The dermal absorption in humans is 9% for low exposures and 2% for high
exposures.  There are no animal feed items associated with these
proposed new uses based upon labeled restrictions against grazing and
harvest for feed.]

	7. Metabolite toxicology. [The major metabolites of fluazifop-p-butyl
are fluazifop acid (free and conjugated), 5-trifluromethyl-2-pyridone
and 2-(4-hydroxyphenoxy) propionic acid (free and conjugated). Based on
their structures, these compounds are unlikely to be significantly less
toxic than parent.]

	8. Endocrine disruption. [The USEPA 2005 HED review of
fluazifop-p-butyl indicated that there was no estrogen, androgen and/or
thyroid mediated toxicity shown in the available toxicity tests. “The
only evidence for potential endocrine effects were effects on the testes
and uterine weight decrement. In an attempt to determine a reason for
these potential endocrine effects, estrogen and androgen agonism and
antagonism were studied in vitro, through incorporation of human
receptors in the DNA of yeast cells. None was found. A study at
sufficiently high dose levels and duration to result in peroxisome
proliferation failed to reproduce the testicular weight decrement,
probably because of animal variability seen with fluazifop-p-butyl. This
variability was seen in metabolism studies and two 90-day Wistar rat
studies at comparable dose levels. One showed testicular weight
decrement and the other one did not. It should also be noted that the
endpoints chosen for regulation of chronic dietary concerns were based
on the possible, but unproven, endocrine effects on the testes and
uterine weight decrement. Therefore, reducing the tenfold FQPA factor to
1X was justified by the use of the NOAEL for a dose related potential
functional deficit in the affected organs of the most sensitive
species.”]

C. Aggregate Exposure

he Dietary Exposure Evaluation Model software with the Food Commodity
Intake Database (DEEM-FCID™, version 2.14) from Exponent.  All
consumption data for these assessments was taken from the USDA’s
Continuing Survey of Food Intake by individuals (CSFII) with the 1994-96
consumption database and the Supplemental CSFII children’s survey
(1998) consumption database.  These exposure assessments include all
currently registered uses of fluazifop-p-butyl plus the proposed new
uses on peanuts and dry beans along with the proposed new directions for
use for soybeans, which include the option of both pre- and post-bloom
applications.  Residue data was taken from field trials where
fluazifop-p-butyl was applied at the maximum intended use rate and
samples were harvested at the minimum pre-harvest interval (PHI) to
obtain maximum residue values.  Calculated and projected percent crop
treated (%CT) values were incorporated in these assessments. 
Anticipated residues in meat and milk were calculated by constructing
theoretical worst-case diets, consisting of nutritionally balanced
mixtures of feeds (typically 30% protein and 70% carbohydrates). 
Drinking water estimates were included directly into the dietary
exposure assessment using the higher of the estimated drinking water
concentrations (EDWCs) for surface and ground water.]

	i. Food. [Acute Risk.  The acute assessment was only performed for the
females (13-49 years old) subpopulation as this subpopulation was the
only one for which an acute endpoint was determined.  The acute dietary
risk assessment was performed with an acute reference dose of 0.5
mg/kg-bw/day based on an acute no observable adverse effect level
(NOAEL) of 50 mg/kg/day developmental toxicity study in rats and an
uncertainty factor of 100X.  The 100X safety factor includes intra- and
interspecies variations.  No additional FQPA safety factor was applied. 
The acute assessment was run using DEEM-FCID™ software using field
trail residues and %CT values.  For the purpose of the aggregate risk
assessment, the exposure value was expressed in terms of margin of
exposure (MOE), which was calculated by dividing the NOAEL by the
exposure for the females (13-49 years old) subgroup.  In addition,
exposure was expressed as a percent of the acute reference dose (%aRfD).
 Acute food exposure to the females (13-49 years old) subpopulation
resulted in a MOE of 20,957 (0.48 % of the acute RfD of 0.5
mg/kg-bw/day).  Since the Benchmark MOE for this assessment was 100 and
since the EPA generally has no concern for exposures below 100% of the
RfD, Syngenta believes that there is a reasonable certainty that no harm
will result from acute dietary (food) exposure to residues arising from
the current and proposed uses for fluazifop-p-butyl.

 was run using DEEM-FCID™ software using average field trial residue
values and %CT values.  The chronic dietary risk assessment was
performed for all population subgroups with a chronic reference dose of
0.0074 mg/kg-bw/day based on a two-generation reproduction study in rats
with a NOAEL of 0.74 mg/kg/day and an uncertainty factor of 100X.  The
100-fold safety factor includes intra- and interspecies variations.  No
additional FQPA safety factor was applied.  For the purpose of the
aggregate risk assessment, the exposure values were expressed in terms
of margin of exposure (MOE), which was calculated by dividing the NOAEL
by the exposure for each population subgroup.  In addition, exposure was
expressed as a percent of the chronic reference dose (%cRfD).  Chronic
food exposure to the U.S. population resulted in a MOE of 10,960 (0.9%
of the chronic RfD of 0.0074 mg/kg-bw/day).  Chronic food exposure to
the most exposed sub-population (children, 1-2 years old) resulted in a
MOE of 5,028 (2.0% of the chronic RfD of 0.0074 mg/kg-bw/day).  Since
the benchmark MOE for this assessment was 100 and since EPA generally
has no concern for exposures below 100% of the RfD, Syngenta believes
that there is a reasonable certainty that no harm will result from
chronic dietary (food) exposure to residues arising from the current and
proposed uses for fluazifop-p-butyl.

Cancer Risk.  Fluazifop-p-butyl has been classified as “not likely
carcinogen to humans”.  Therefore no dietary cancer assessment was
performed.]

	ii. Drinking water. [The Estimated Drinking Water Concentrations
(EDWCs) of fluazifop-p acid were determined using Tier l SCI-GROW which
estimates pesticide concentration in ground water and Tier II PRZM/EXAMS
which estimates pesticide concentration in surface water.  The modeling
was conducted using environmental fate parameters by applying EPA’s
guidance to identify the highest EDWCs from current or proposed labeled
use rates for fluazifop-p-butyl.  The input parameters all represent
physical-chemical and fate properties of fluazifop-p acid.  The
application rates were also adjusted for the molecular weight ratio
between the acid and parent.

For ground water, the current registered tree fruit use rate of 1.125 lb
a.i./A/year (0.96 lb a.i./A/year, adjusted for molecular weight) gave
the highest EDWCs.  The SCI-GROW output provided an EDWC (acute and
chronic) of 9.94E-02 ppb for ground water.  For surface water, the
proposed peanut crop use rate pattern of 0.375 lb a.i./A (0.32 lb
a.i./A, adjusted for molecular weight) with two applications at a 14 day
interval gave the highest EDWCs.  Employing the NC peanut standard PRZM
scenario, the PRZM/EXAMS output provided EDWCs of 30.471 ppb and 6.329
ppb for acute and chronic surface water, respectively.  These surface
water values have been corrected for 0.87 Percent Cropped Area (PCA). 
Since the surface water EDWCs exceed the ground water EDWC, the
PRZM/EXAMS surface water values will be used for risk assessment
purposes and will be considered protective for any ground water
concentration concerns.

 The acute surface water EDWC of 30.471 ppb was input directly into the
DEEM-FCID™ software as “water, direct and indirect, all sources”
to model the acute drinking water exposures.  Exposure contributions at
the 99.9%-ile of exposures were determined by taking the difference
between the aggregate (food + drinking water) exposures and the food
(alone) exposures for each population subgroup.  Acute drinking water
exposure to the females (13-49 years old) subpopulation resulted in a
MOE of 22,946 (0.44% of the acute RfD of 0.5 mg/kg-bw/day).  Since the
benchmark MOE for this assessment was 100 and since EPA generally has no
concern for exposures below 100% of the acute RfD, Syngenta believes
that there is a reasonable certainty that no harm will result from acute
drinking water exposure to residues arising from the current and
proposed uses for fluazifop.

Chronic Exposure from Drinking Water.  The chronic surface water EDWC of
6.329 ppb was input directly into the DEEM-FCID™ software as “water,
direct and indirect, all sources” to model the chronic drinking water
exposures.  Chronic drinking water exposure to the U.S. population
resulted in a MOE of 5,564 (1.80% of the chronic RfD of 0.0074
mg/kg-bw/day).  Chronic drinking water exposure to the most exposed
sub-population (infants, <1 year old) resulted in a MOE of 1,689 (5.92%
of the chronic RfD of 0.0074 mg/kg-bw/day).  Since the Benchmark MOE for
this assessment was 100 and since EPA generally has no concern for
exposures below 100% of the chronic RfD, Syngenta believes that there is
a reasonable certainty that no harm will result from chronic drinking
water exposure to residues arising from the current and proposed uses
for fluazifop-p-butyl.]

	2. Non-dietary exposure. [Fluazifop-p-butyl is a selective herbicide
used in the post-emergent control of grasses in agricultural,
ornamental, residential and recreational (golf course) settings.  A
residential exposure and risk assessment was performed for
fluazifop-p-butyl uses on turf and ornamentals using the endpoints and
uncertainty factors established by the EPA.  The fluazifop-p-butyl
end-use products are formulated as both liquid concentrates and
ready-to-use (RTU) liquids.  Homeowners can apply the liquid
formulations using a low pressure handwand (LPHW) or a hose-end sprayer
with either a dial type spray attachment (DTS) or a sprinkler
attachment.  Homeowners can apply the RTU liquids using a hose end
sprayer with a sprinkler attachment or a trigger-pump sprayer.  The
homeowner handler and residential post-application exposure and risks
were determined based on the highest use rates for all lawn and garden
products that contain fluazifop-p-butyl.  Based on the labels for the
various products containing fluazifop-p-butyl, there is a potential for
residential handler exposure from consumers making applications to home
lawns and ornamentals.  There is also a potential for post-application
residential exposure to adults and children re-entering treated lawns
and to adults and youths playing golf on treated turf.  The following
endpoints were used in these residential risk assessments:  NOAEL = 100
mg/kg/day (short-term incidental oral endpoint from a developmental
toxicity study in rats) and NOAEL = 2 mg/kg/day (short-term dermal
endpoint from a developmental toxicity study in rats), and NOAEL = 2
mg/kg/day (short-term inhalation endpoint from a developmental toxicity
study in rats).  The resultant combined short-term MOEs were 243 (adult
handler risk for hose-end-dial type sprayer) and 250 (combined total
post-application risk for children 1-6 years old).  Both children (1-6
years old) and adults (20-49 years old) MOEs are above the benchmark MOE
of 100 and thus do not exceed the EPA’s level of concern.]

D. Cumulative Effects

	[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 EPA does not have, at this time,
available data to determine whether fluazifop-p-butyl 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, the EPA has not assumed that fluazifop-p-butyl has a
common mechanism of toxicity with other substances.]

E. Safety Determination

B*

B*

B*

B*

²

³

Ç

È

ø

ù

(

)

±

³

Æ

È

ø

ù

ü

ý

B*

B*

B*

B*

B*

B*

;

=

Ó

Ô

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

B*

,ent and proposed uses of fluazifop-p-butyl provided a MOE of 10,952
(0.91% of the chronic RfD of 0.5 mg/kg-bw/day) for the females (13-49
years old) subpopulation.  Since the aggregate MOEs exceed the Benchmark
MOE of 100, Syngenta believes that there is a reasonable certainty that
no harm will occur to the U.S. Population and the females (13-49 years
old) subpopulation from chronic or acute aggregate exposures arising
from the current and proposed uses for fluazifop.]

	2. Infants and children. [Using the conservative assumptions described
in the exposure section above, and based on the completeness and
reliability of the toxicity data, the chronic aggregate exposure
calculation for current and proposed uses of fluazifop-p-butyl provided
a MOE of 1,521 (6.6% of the chronic RfD of 0.0074 mg/kg-bw/day) for the
infants < 1 year old (the most sensitive population subgroup for the
chronic assessment).  No acute aggregate exposure calculation was
performed for the infants and children subgroups for the chronic
assessment, since no acute endpoint was determined for these subgroups. 
Since the aggregate MOEs exceed the benchmark MOE of 100, Syngenta
believes that there is a reasonable certainty that no harm will occur to
infants and children from the chronic aggregate exposures arising from
the current and proposed uses for fluazifop.]

F. International Tolerances

	[No Codex maximum residue levels (MRLs) have been established for
residues of fluazifop-P-butyl or fluazifop-butyl; therefore, issues of
compatibility do not exist. International MRLs for the herbicide
fluazifop and fluazifop-p-butyl have been established for various
agricultural commodities in a number of countries including but not
limited to Australia, Czech Republic, Denmark, Luxembourg, Netherlands,
and Sweden]

 PAGE   

 PAGE   11