 

<EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE
PETITIONS PUBLISHED IN THE FEDERAL REGISTER  >

<EPA Registration Division contact: John Bazuin, (703) 305-7381>

 

<TEMPLATE:>

<  SEQ CHAPTER \h \r 1 ISK Biosciences Corporation>

<Petition Number 9F7571>

<	EPA has received a pesticide petition (PP 9F7571) from ISK Biosciences
Corporation, 7470 Auburn Road, Suite A, Concord, Ohio, 44077, 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 by establishing a
tolerance for residues of the fungicide fluazinam, (3-chloro- N
-[3-chloro-2,6-dinitro-4-(trifluoromethyl)
phenyl]-5-(trifluoromethyl)-2-pyridinamine), and the metabolite AMGT,
3-[[4-amino-3-[[3-chloro-5-(trifloromethyl)-2-pyridinyl]amino]-2-nitro-6
-(trifluoromethyl) phenyl] thio]-2-(beta-D-glucopyranosyloxy) propionic
acid), in or on the raw agricultural commodity apples at 1.7 parts per
million (ppm); in or on the feed commodity apple, pomace, wet, at 5.0
ppm; and by establishing tolerances for the combined residues of
fluazinam and its metabolites, DAPA and AMPA in the following animal
tissues and meat byproducts: cattle, fat at 0.03 ppm; cattle, kidney at
0.03 ppm; cattle, liver at 0.03 ppm; cattle, meat at 0.03 ppm; cattle,
meat byproducts at 0.03 ppm; goat, fat at 0.03 ppm; goat, kidney at 0.03
ppm; goat, liver at 0.03 ppm; goat, meat at 0.03 ppm; goat, meat
byproducts at 0.03 ppm; horse, fat at 0.03 ppm; horse, kidney at 0.03
ppm; horse, liver at 0.03 ppm; horse, meat at 0.03 ppm; horse, meat
byproducts at 0.03 ppm; milk at 0.03 ppm; sheep, fat at 0.03 ppm; sheep,
kidney at 0.03 ppm; sheep, liver at 0.03 ppm; sheep, meat at 0.03 ppm;
and sheep, meat byproducts at 0.03 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>

<Plant metabolism.   SEQ CHAPTER \h \r 1 The residue of concern is best
defined as the parent, fluazinam in most crops and as the parent,
fluazinam and its metabolite, AMGT, in fruit crops (apple, grape and
blueberry).    SEQ CHAPTER \h \r 1 The metabolism of fluazinam in plants
(potatoes, peanuts, apples and wine grapes) is adequately understood for
the purposes of these tolerances.  The metabolism of fluazinam in peanut
and potato involves initial reduction of the nitro groups, hydrolysis of
the trifluoromethyl group as well as replacement of chlorine by
glutathione with subsequent reactions along the glutathione pathway. 
Ring cleavage occurs following replacement of the deactivating NO2 and
Cl groups with activating groups such as OH, NH2 and sulfhydryl.  Parent
fluazinam is then rapidly degraded to form CO2 and carbon fragments
which are incorporated into natural products such as glucose, fructose,
sucrose, oils and protein.  Thus, parent fluazinam is either not found
or barely detectable in peanuts and potatoes.  Fluazinam parent was the
major identifiable residue in both the grape and apple metabolism
studies.  However, minor levels of AMGT (less than 5% of the total
radioactive residue) were also formed in grapes and apples.  In grape
and apple metabolism studies, following reduction of the nitro groups
and replacement of chlorine with a sulfur containing side-chain such as
glutathione (as occurred in peanuts and potatoes), glucose is attached
to the thiolactic acid conjugate of AMPA to form the metabolite known as
AMGT.  This metabolite was not found in   SEQ CHAPTER \h \r 1 the peanut
or potatoes metabolism studies.  It is analogous to the cysteine
conjugate of AMPA found in rats.  Identifiable residues in plant
metabolism studies either closely resemble fluazinam in structure or are
the result of re-incorporation of the fluazinam carbon pool into natural
products. 

    Ruminant and poultry metabolism studies demonstrated that the
transmittal of residues from the feed of goats and hens through to meat,
milk, and eggs was low.  Total 14C residues were below 1 ppm in all
tissues, milk and eggs.  Identifiable residues were less than 2% of the
administered dose in all matrices, except for chicken fat and liver. 
The major metabolites found in animal tissues and milk were DAPA, AMPA,
and their sulfamate conjugates.  Parent Fluazinam was only detected in
very small amounts.>

<	2. Analytical method. An analytical method using gas chromatography
with electron capture detection (GC-ECD) for the determination of
fluazinam residues on apples has been developed and validated.  The
method involves solvent extraction followed by liquid-liquid
partitioning and concentration prior to a final purification using
column chromatography.  The method has been successfully validated by an
independent laboratory using peanut nutmeat as the matrix.  The limit of
quantitation (LOQ) of the method is 0.01 ppm in apple.  AMGT was
analyzed using a separate sample or aliquot of extract with an HPLC-UV
detection system.  >

<	3. Magnitude of residues. Apple. A total of 20 field trials were
conducted on apples.  Treatment 02 of each field site consisted of ten
(10) foliar applications at the target rate of approximately 0.45 lb
a.i./A, applied at 7 (+2) day intervals.  Apples were harvested 28 - 32
days after the last application.   Two decline trials were also included
with sampling at 0, 7, 14, 21 and 28 days after the last application. 
The results show that all residues (Fluazinam + AMGT) in apples
following a total of approximately 3.97 lb a.i./A to 5.40 lb
a.i./A/season with an average PHI of 30 days, ranged from <0.01 ppm
(LOQ) to 1.69 ppm.  The mean combined residue of fluazinam and AMGT was
0.23 ppm.  In the processing study, fluazinam residues concentrated in
both the wet (2.8) and dry (3.7) pomace relative to whole apples. 
Fluazinam was not detected in either raw juice or pasteurized cider.  >

<B. Toxicological Profile>

<	1. Acute toxicity.  A battery of acute toxicity studies was conducted
which placed technical fluazinam in Toxicity Category III for oral LD50,
dermal LD50, dermal irritation, Category II for inhalation LC50 and
Category I for eye irritation.  Technical fluazinam showed potential for
dermal sensitization.  In an acute neurotoxicity study, the NOAEL for
neurotoxicity was 2000 mg/kg bw (the highest dose tested) and the NOAEL
for systemic effects was 50 mg/kg bw.>

<	2. Genotoxicty. A battery of tests has been conducted to assess the
genotoxic potential of technical fluazinam.  Assays conducted included
two gene mutation tests in bacteria, a chromosomal aberration test in
mammalian cells, a mouse micronucleus test and a DNA repair test in
bacteria.  Technical fluazinam did not elicit a genotoxic response in
any of the studies conducted.>

<	3. Reproductive and developmental toxicity. In a two-generation
reproductive toxicity study, the NOAEL for reproductive effects was 100
ppm (10.6 mg/kg bw/day).  The NOAEL for parental toxicity was 20 ppm
(1.9 mg/kg bw/day).>

    In a rat developmental study, there were no developmental effects
observed at non-maternally toxic doses.  The developmental NOAEL was 50
mg/kg bw/day and the LOAEL was 250 mg/kg bw/day, based upon decreased
mean fetal body weight and other evidence suggestive of delayed fetal
development related to maternal toxicity. The maternal NOAEL was shown
to be 50 mg/kg bw/day. 

    In a rabbit developmental study, there were no developmental effects
observed at non-maternally toxic doses.  The developmental NOAEL was 7
mg/kg bw/day and the LOAEL was 12 mg/kg bw/day, based on increased
incidence of total litter loss and possible slightly increased
incidences of fetal findings at this dose.  It was concluded that the
maternal NOAEL was 4 mg/kg bw/day.

<	4. Subchronic toxicity. The NOAEL for the 13-week feeding study in
rats was 50 ppm (3.8 mg/kg bw/day in males, 4.3 mg/kg bw/day in
females).  The LOAEL was 500 ppm (38 mg/kg bw/day in males, 44 mg/kg
bw/day in females), based on periacinar hepatocellular hypertrophy and
sinusoidal chronic inflammation in males, increased liver weights in
males and increased lung weights in females.

    In a 13-week dog study, the NOAEL was 10 mg/kg bw/day.  The LOAEL
was 100 mg/kg bw/day, based on ocular change observed
ophthalmoscopically and liver effects consisting of increased relative
liver to body weight, bile duct hyperplasia with or without
cholangiofibrosis and increased plasma phosphatase levels.

    In a 21-day dermal study, the NOAEL for systemic effects was 10
mg/kg bw/day.  The LOAEL was 100 mg/kg bw/day, based on hepatocelluar
hypertrophy and increases in AST and cholesterol levels. 

    In a subchronic neurotoxicity study, no effects considered to be
indicative of neurotoxicity were observed at the highest dose tested,
3000 ppm (233 mg/kg bw/day in males, 280 mg/kg bw/day in females).  The
NOAEL for systemic toxicity (body weight differences) was 1000 ppm (74
mg/kg bw/day). 

    In a developmental neurotoxicity study in rats, fluazinam was
administered by gavage to female rats from Day 6 after mating to Day 20
of lactation and additionally to their offspring from Day 7 of age to
Day 20 or 21 of age.  The author concluded that the maternal NOAEL was 2
mg/kg bw/day based on reduced body weights and lower food intake.  No
effects were seen on the microscopic structure of the nervous system of
the dams at any dose level (maximum dose of 50 mg/kg bw/day).  The NOAEL
for behavior and nervous system of the dams was >50 mg/kg bw/day, the
highest dose tested.  No adverse effect of treatment at any dose level
was seen on number of implantations, litter size or offspring survival. 
Signs of general toxicity in the offspring were evident based on lower
Day 1 body weights and lower weight gains at 10 and 50 mg/kg bw/day
through weaning.  The NOAEL for general toxicity to offspring was 2
mg/kg bw/day.  There was no evidence of developmental neurotoxicity in
the offspring.  The NOAEL for the functional and morphological
development of the nervous system in the offspring was >50 mg/kg bw/day,
the highest dose tested.  There was no increased sensitivity of the
fetus or young rat pups to fluazinam as compared to the dams.>

<	5. Chronic toxicity. Fluazinam was not carcinogenic in rats.  A NOAEL
of 10 ppm (Males: 0.38 mg/kg bw/day; Females: 0.47 mg/kg bw/day) of
fluazinam was established based on the following effects at 1000 and/or
100 ppm: lower food consumption and efficiency of food utilization,
slight anemia, elevated cholesterol, increased liver weights, an
increased number of macroscopic liver and testes lesions and an
increased incidence of microscopically observed lung, liver, pancreas,
lymph node and testes lesions.

    An additional study was conducted to further define the NOAEL for
long-term effects in the rat.  In the second study, a NOAEL of 50 ppm
(2.2 mg/kg bw/day) was established based on liver and testes effects.

    Two long-term feeding studies were conducted in mice.  In the first,
the NOAEL for all effects was 10 ppm (Males: 1.1 mg/kg bw/day; Females:
1.2 mg/kg bw/day) and the LOAEL was 100 ppm (Males: 10.7 mg/kg bw/day;
Females: 11.7 mg/kg bw/day) based on the treatment-related effects
observed in the liver.

    A second oncogenicity study in mice was conducted at 1000, 3000 and
7000 ppm to ensure that an MTD dose was studied.  Findings included
increased female mortality, reduced body weight gains, increased brain
weights and/or liver weights.  An impurity in the test material used in
this study resulted in vacuolation of the white matter of the brain and
cervical spinal cord in treated animals. A statistically significant
higher incidence of hepatocellular adenomas was observed in the 3000 ppm
dose males.  Hepatocellular adenomas are common tumors in male mice. 
There was no dose relationship in the induction of the adenoma and no
increase in hepatocellular carcinomas.  It was concluded that fluazinam
is not carcinogenic in the mouse. 

    In a chronic dog study, the NOAEL was determined to be 1 mg/kg
bw/day.  The LOAEL was 10 mg/kg bw/day based on generalized, nonspecific
toxicity.  No ocular effects were observed ophthalmoscopally at any dose
in this study.>

<	6. Animal metabolism. After an oral dose of fluazinam the median peak
time for blood concentration of radiolabel activity for both sexes was 6
hours.  The major route of excretion was the feces with urine
contributing as a minor route. Less than 1% of the administered dose was
found in the terminated animals.  The highest concentration in tissues
was found in the liver.  There were no major differences related to sex
or dose level in the findings.  It was concluded that fluazinam is
metabolized by both reduction and glutathione and glucuronide
conjugation and further metabolism.>

<	7. Metabolite toxicology. The same metabolic processes occur in plants
and animals but metabolism in plants is more extensive than in animals.
All of the major identified metabolites in both plants and animals
retain the phenylpyridinylamine structure.  Many of the metabolites
resulting from fluazinam are similar in plants and animals and,
therefore, have already been evaluated toxicologically.  

    Because of the rapid and complete elimination (in animals) and
re-incorporation (in plants) of fluazinam, the toxicity of metabolites
is expected to be similar to but lower than the toxicity of the parent
compound.  The residue of concern is parent fluazinam only in most crops
and parent fluazinam plus its minor metabolite AMGT on/in fruit crops
such as apple, grape and blueberry.>

<	8. Endocrine disruption. The toxicological profile of fluazinam shows
no evidence of physiological effects characteristic of the disruption of
the hormone estrogen in mammalian chronic studies or in mammalian or
avian reproduction studies.   It is therefore considered that there is
an adequate level of safety over the reference dose for possible
endocrine effects and that an additional safety factor for possible
endocrine effects is not warranted.>

<C. Aggregate Exposure>

<	1. Dietary exposure. Potential dietary exposures from food were
estimated using the proposed tolerances for all crops using the Dietary
Exposure Evaluation Model-Food Consumption Intake Database (DEEM-FCIDTM)
and percent crop treated of 100% (with the exception of imported wine
grapes as discussed below).  The following raw agricultural commodities
were included: apple, carrot,  brassica (cole) leafy vegetables (Group
5) including turnip greens, bean (Groups 6A, 6B and 6C), bushberry
(Group 13-07B), ginseng, head lettuce, leaf lettuce, bulb onion (Crop
3-07A), peanut, potato, imported wine grapes and sherry and resulting
secondary residues in meat and milk.  For acute dietary exposure, the
acute population adjusted dose (aPAD) was based on the NOAEL of 50 mg/kg
bw/day from an acute rat neurotoxicity study.   For females 13-49 years
of age, the NOAEL of 7 mg/kg bw/day from the rabbit developmental
toxicity study was used for acute dietary exposure.  For chronic dietary
exposure, the chronic population adjusted dose (cPAD) was based on the
NOAEL from the mouse carcinogenicity study (1.1 mg/kg bw/day).  An
uncertainty factor of 100 was used in both cases since the results of a
DNT study confirmed there was no increased sensitivity of the fetus or
young rat pups to fluazinam as compared to the dams and the FQPA
uncertainty factor could be reduced to one (1).>

<	i. Food. Acute Risk Tier 1 acute dietary exposure analyses were
conducted for fluazinam to determine the exposure contribution of the
above mentioned commodities to the diet and to ascertain the acute risk
potential.  The estimates were based on: proposed tolerance level
residues for all the crops; apple, peanut and potato processing studies;
market share assumptions of 100% crop treated (except wine grapes where
it was assumed that 100% of the imported wine grapes would be treated
and 39% of wine consumed in the US is imported); and consumption data
from USDA’s CSFII (1994 through 1998) continuing survey of food
intake.

    Even using all of the worst-case exposure scenarios listed above,
the Tier 1 95th percentile acute dietary exposure (per capita) for the
U.S. population was estimated to be 0.016260 mg/kg bw/day or 3.25% of
the aPAD. The highest acute exposure estimate (95th percentile) was
observed in the females 13-49 yrs. subpopulation: 0.011259 mg/kg bw/day.
 This corresponds to only16.08% of the aPAD.

    Chronic Risk Tier 1 dietary exposure analyses were conducted for
fluazinam to determine the exposure contribution of the above mentioned
commodities to the diet and to ascertain the chronic risk potential. The
estimates were based on: proposed tolerance level residues for all the
crops; apple, peanut and potato processing studies; market share
assumptions of 100% crop treated (except wine grapes where it was
assumed that 100% of the imported wine grapes would be treated and 39%
of wine consumed in the US is imported); and consumption data from
USDA’s CSFII (1994 through 1998) continuing survey of food intake.

    Even using all of the worst-case exposure scenarios listed above,
the Tier 1 chronic dietary exposure estimates resulted in an estimated
exposure for the U.S. population of 0.001360 mg/kg bw/day.  This
exposure corresponds to 12.4% of the cPAD of 0.011mg/kg bw/day.  The
highest exposure estimate was calculated for the all infants (<1 year)
population subgroup.  This exposure was determined to be 0.004022 mg/kg
bw/day (36.6% of the cPAD).

    It can be concluded that acute or long-term dietary exposure to
fluazinam through residues on treated apple, carrot,  brassica (cole)
leafy vegetables (Group 5) including turnip greens, bean (Groups 6A, 6B
and 6C), bushberry (Group 13-07B), ginseng, head lettuce, leaf lettuce,
bulb onion (Crop 3-07A), peanut, potato, imported wine grapes and sherry
should not be of cause for concern.>

<	ii. Drinking water. Since fluazinam is intended for application
outdoors to field grown crops, the potential exists for parent and/or
metabolites to reach ground or surface water that may be used for
drinking water.  The potential estimated drinking water concentrations
(EDWCs) associated with the application of fluazinam to apples is less
than the maximum values estimated for blueberries.  Thus, the more
conservative EDWCs for blueberries were incorporated into the DEEM-FCID
model to estimate dietary exposure.>

<	2. Non-dietary exposure. No petition for registration of fluazinam is
being made for either indoor or outdoor residential use. 
Non-occupational exposure of fluazinam to the general population is
therefore not expected and is not considered in aggregate exposure
estimates.>

<D. Cumulative Effects>

<	Fluazinam is a phenylpyridinylamine fungicide.   Since there are no
other members of this class of fungicides, it is considered unlikely
that fluazinam would have a common mechanism of toxicity with any other
pesticide in use at this time.>

<E. Safety Determination>

<	1. U.S. population. Based on a NOAEL of 1.1 mg/kg bw/day from the
mouse carcinogenicity study, and using an uncertainty factor of 100, a
reference dose (RfD) of 0.011 mg/kg bw/day is proposed for assessment of
long-term risk.  Since the results of a DNT study confirmed there was no
increased sensitivity of the fetus or young rat pups to fluazinam as
compared to the dams, the FQPA uncertainty factor could be reduced to
one (1) and the cPAD is equivalent to the RfD.  The estimate of dietary
intake was based on: proposed tolerance level residues for all the
crops; apple, peanut and potato processing studies; market share
assumptions of 100% crop treated (except wine grapes where it was
assumed that 100% of the imported wine grapes would be treated and 39%
of wine consumed in the US is imported); and consumption data.  The
estimated chronic exposure of fluazinam from drinking water is 17.7 ppb.
 Even using those conservative intake estimates, the proposed tolerances
plus drinking water will utilize only 12.4% of the RfD or cPAD for the
U.S. population.  Using these same conservative exposure assumptions,
the acute dietary exposure estimates and the acute DWEC of 71 ppb are
well below the aPAD of 0.5 mg/kg bw/day.  Based on this information, it
can be concluded that there is reasonable certainty that no harm will
result from acute or chronic exposure to fluazinam.>

<	2. Infants and children. Data from developmental toxicity studies in
the rat and rabbit, a 2-generation reproduction study and a
developmental neurotoxicity study were considered.  These studies, which
were described earlier, demonstrated no increased sensitivity of rats or
rabbits to in utero or gavage exposure of pups to fluazinam.  In
addition, the multigeneration reproductive toxicity study did not
identify any increased sensitivity of rats to in utero or postnatal
exposure.  For all four studies, parental NOAELs were lower than or
equivalent to the developmental or offspring NOAELs.  It is concluded
that the standard margin of safety will protect the safety of infants
and children and that an additional FQPA safety factor is not warranted.


    The dietary exposure of fluazinam to infants and children is
estimated to be low. The proposed tolerances plus drinking water input
will utilize only 12.17% of the aPAD for the “All Infants” subgroup,
and only 13.43% of the cPAD for the subgroup “Children (1-2 years)”.
 Thus, it can be concluded that there is reasonable certainty that no
harm will result to infants and children from acute or chronic exposure
to fluazinam.>

<F. International Tolerances>

<	There are presently no Codex maximum residue levels (MRLs) established
for residues of fluazinam on any crop.  The Canadian and Mexican MRLs
for beans and potatoes are similar to the tolerances established for
these crops in the USA.>

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