Document ID: EPA-HQ-OPP-2007-0312-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-06-27T04:00Z

<EPA Registration Division contact: Sidney Jackson (703) 305-7610>

 

Interregional Research Project Number 4 (IR-4)

<PP 7E7183>

<	EPA has received a pesticide petition (PP) [7E7183] from IR-4, 500
College road East, Suite 201 W, Princeton, NJ 08540 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 180.476>

<	by establishing a tolerance for combined residues of the fungicide
triflumizole,
1-(1-((4-chloro-2-(trifluoromethyl)phenyl)imino)-2-propoxyethyl)-1 H
-imidazole, and its metabolites containing the
4-chloro-2-trifluoromethylaniline moiety, calculated as the parent
compound, >

<	in or on the raw agricultural commodity leafy brassica (subgroup 5B)
at 20 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 the FDDCA; however, EPA has not fully evaluated the
sufficiency of the submitted data at this time or whether the data
support granting of the petition. Additional data may be needed before
EPA rules on the petition.>

<A. Residue Chemistry>

<	1. Plant metabolism. In crops, the metabolism of  [14C]-Phenyl]
triflumizole was investigated in cucumber, pears, grapes and apples. The
major metabolites were:
N-(4-chloro-2-trifluoromethylphenyl)-n-propoxyacetamidine  (FM-6-1),
N-(4-chloro-2-trifluoromethyphenyl)-n-propoxyacetanilide  (FD-1-1) and
the free or conjugated products of
N-(4-chloro-2-trifluoromethylphenyl)-hydroxyacetamidine (the
O-dealkylation product of FM-6-1),
N-(4-chloro-2-trifluoromethylphenyl)-hydroxyacetanilide (FD-2-1)  and
the triflumizole aniline (FA-1-1).

>

<	2. Analytical method. The analytical method is suitable for analyzing
crops for residues of triflumizole and its aniline containing
metabolites at the proposed tolerance levels.  The analytical method has
been independently validated.  Residue levels of triflumizole are
converted to FA-1-1 by acidic and alkaline reflux, followed by
distillation.  Residues are then extracted and subjected to SPE
purification.  Detection and quantitation are conducted by a gas
chromatograph equipped with nitrogen phosphorus detector, electron
capture detector or mass spectrometry detection.  The limit of
quantitation of the method has been determined at 0.05 ppm for the
combined residues of triflumizole and FA-1-1 in mustard greens.  The
enforcement methodology has been submitted to the Food & Drug
Administration for publication in the Pesticide Analytical Manual, Vol.
II (PAM II).>

<	3. Magnitude of residues. Section 3 registrations for triflumizole is
currently exist for several commodities (e.g., apple, cherry, filbert,
grape, pear, strawberry, cucurbits, and meat, milk, poultry and eggs)
and feed items.  The subject of the August 23, 2006, Federal Register
notice regarding triflumizole was the establishment and/or extension of
emergency exemption tolerances on several crops in Texas (i.e., parsley
leaves, dandelion leaves, swiss chard, collards, kale, kohlrabi, mustard
greens, Chinese napa cabbage, broccoli, coriander leaves and turnip
greens).   Many of these crops are in subgroup 5B, so the purpose of
this dietary assessment is to expand the uses of triflumizole to all
crops in 5B.  The proposed group tolerance for leafy brassica vegetables
(subgroup 5B) is 20 ppm.>

<B. Toxicological Profile>

<	1. Acute toxicity. The database includes the following studies for
triflumizole technical: a rat acute oral study with a LD50 of 2.23 g/kg;
a rabbit acute dermal study with a LD50 >2 g/kg; a rat acute inhalation
study with a LC50 >5.3 mg/l; a rabbit primary ocular irritation study
which showed moderate irritation; a rabbit primary dermal irritation
study which showed no irritation; a guinea pig dermal sensitization
study which showed slight dermal sensitization potential.  The database
also includes the following studies for Procure 480SC:  a rat acute oral
study with a LD50 of > 2 g/kg; a rabbit acute dermal study with a LD50
>5 g/kg; a rat acute inhalation study with a LC50 >3.7 mg/l; a rabbit
primary ocular irritation study which showed slight irritation; a rabbit
primary dermal irritation study which showed no irritation; a guinea pig
dermal sensitization study which was negative for skin sensitization. 
Acute neurotoxicity study of triflumizole in rats.  Male and Female rats
were administered a single dose of triflumizole by oral gavage at levels
of 0, 25, 100, 200 (female) and 400 (male) mg/kg and observed for 15
days.  Decreased motor activity was noted 3 to 6 hours post exposure in
male and female rats at 100 mg/kg and above.  Functional Observational
Battery (FOB) effects included a decrease rearing counts in females,
decreases in forelimb and hind limb grip strength in males and forelimb
grip strength in females at 100 mg/kg and above.  The NOAEL was
considered to be 25 mg/kg based on clinical findings and functional
observational battery evaluations at 100 mg/kg.>

<	2. Genotoxicty. Triflumizole was negative in all genotoxicity assays
including: Ames assay in S. typhimurium, gene conversion assay in yeast
strain D4, REC assay in B. subtilis, unscheduled DNA synthesis (UDS)
assay in cultured rat hepatocytes, chromosome aberration assay in
cultured Chinese hamster ovary (CHO) cells and a mouse micronucleus
assay.>

<	3. Reproductive and developmental toxicity. In a developmental
toxicity study, triflumizole was administered by oral gavage to
pregnant, female Sprague Dawley rats at dosage levels of 0, 10, 35 or
120 mg/kg/day.  Maternal toxicity, as evidenced by a substantial
reduction in body weight gain, was seen at 35 and 120 mg/kg/day. At
these dosage levels there was a decrease in fetal viability in the form
of late resorptions. There were no teratogenic effects.  The no observed
adverse effect level (NOAEL) for maternal and developmental toxicity was
10 mg/kg/day. Triflumizole was also administered by oral gavage to
pregnant, female New Zealand White rabbits at dosage levels of 0, 5, 25,
or 50 mg/kg/day.  At a dose level of 50 mg/kg/day there was a reduction
in body weight gain in kits. There were no developmental or teratogenic
effects. The NOAEL for maternal toxicity was 25 mg/kg/day and the NOAEL
for developmental toxicity was greater than 50 mg/kg/day. The
reproductive toxicity of triflumizole was evaluated in a rat
reproduction study, conducted on three generations, at dietary
concentrations of 0, 30, 70 and 170 ppm .  Fertility was not affected by
treatment.  There was an increase in placental weight in the F1b, F2b
and F3b litters and a statistically significant increase in gestation
length in the high dose group at the F1a interval and at all three dose
levels at the F3a interval.  The NOEL for reproductive effects in this
study is 70 ppm, which was the original conclusion of the study director
at Life Science Research.  This is based on the increase in gestation
length seen at 170 ppm in two of six matings.  In addition, the NOEL for
systemic parental toxicity was greater than 170 ppm and the NOEL for
developmental toxicity was 70 ppm based upon increased incidences of
hydroureter and space between the body wall and organs.]>

<	4. Subchronic toxicity. To assess sub-acute dermal toxicity,
triflumizole was applied to the backs of male and female Sprague Dawley
rats for three weeks.  High dose female rats exposed to 1,000 mg/kg/day
exhibited mild fatty vacuolation in the liver, which was within the
range of normal biological variation.  Therefore, the NOAEL for
sub-acute dermal toxicity in rats was greater than 1,000 mg/kg/day.  90
Day Neurotoxicity Study of Triflumizole in Rats.  Male and female rats
were administered triflumizole in the diet at levels of 70, 700 or 2000
ppm (4.1, 40.9, 117.3 mg/kg/day male and 4.9, 47.8 and 133.3 mg/kg/day
females) for a period of 90 days.  The NOAEL for general toxicity was 70
ppm (4.1, 4.9 mg/kg/day males and females respectively) based on body
weight (significantly higher in males at 700 ppm and significantly lower
in females at 2000 ppm), food consumption (lower in females at 2000
ppm), hematology (Hb, Hct and/or rbc values were slightly lower in males
and females at 2000 ppm and at week 4 in the 700 ppm dose group) and
pathology evaluations (higher mean and relative liver weights in males
and females at 700 and 2000 ppm, hepatocellular hypertrophy in males and
females at 700 and 2000 ppm).  The NOAEL for neurotoxicity was 2000 ppm
(117.3, 133.3 mg/kg/day males and females respectively).>

<	5. Chronic toxicity. Triflumizole was fed to male and female Beagle
dogs for one year at dietary concentrations of 0, 100, 300 and 1,000 ppm
to assess chronic toxicity.  At a dosage level of 1,000 ppm there was an
increase in serum liver enzymes and a decrease in RBC concentration. The
NOAEL for chronic toxicity in dogs was 300 ppm (7.5 mg/kg/day).  
Triflumizole was fed to male and female Sprague Dawley rats for two
years at dietary concentrations of  0, 100, 400 and 1,600 ppm to assess
chronic toxicity. At the high dose level there was a substantial
reduction in body weight gain in males and females. At the mid and high
dose levels there was an increase in liver weight. Ovary weight was
increased in high dose female rats, and kidney weights were elevated in
high dose animals.  Alanine amino-transferase and lactose dehydrogenase
were elevated in high dose males and females, respectively.  High dose
females had an increased incidence of ovarian follicular cysts, while
high dose males exhibited pancreatic acinar cell atrophy. Fatty
vacuolization of the liver was seen at all dose levels and hepatocytic
hypertrophy was seen in high and mid-dose males and females. Female rats
given 400 or 1,600 ppm had an increased incidence of basophilic
foci/areas of hepatocytic alteration. Effects at 100 ppm were confined
to hepatocytic fatty vacuolation and hypertrophy in females. These
changes were less severe than those seen in rats given 400 or 1,600 ppm
and were considered by the laboratory to be indicative of adaptive
metabolic change. The  dietary level of 100 ppm (5 mg/kg/day) is
considered to be a NOAEL.>

<	6. Animal metabolism. Triflumizole, [14C-Phenyl]
1-(1-((4-chloro-2-trifluoromethylphenyl)imino)-2-propoxyethyl)-1H-imidaz
ole, was found to be rapidly absorbed and excreted in rats. Two days
after oral dosing, 78% was found to be excreted in the urine and 20% in
the feces.  No sex difference was noted. It appears that the loss of the
imidazole ring was the basic step in the metabolic pathway of this
fungicide in mammals. The elimination of the imidazole ring yielded
initially N-(4-chloro-2-trifluoromethylphenyl)-n-propoxyacetamidine
(FM-6-1), and N-(4-chloro-2-trifluoromethylphenyl)-n-propoxyacetanilide 
(FD-1-1). Other hydroxylated metabolites identified (free, or as
sulfate/glucuronide conjugates) included, among others, 
N-(4-chloro-2-trifluoromethylphenyl)-hydroxyacetamidine (FM- 8-1);
4-chloro-2-trifluoromethyl-hydroxyacetanilide (FD-2-1); and 4-chloro-2-
trifluoromethyl-6-hydroxyaniline (FA-1-5).>

<	7. Metabolite toxicology. Both plant and animals produce the same
metabolites that were identified in the metabolism studies; therefore,
the toxicity of the metabolites has essentially been evaluated in the
rat toxicology studies.>

<	8. Endocrine disruption. In the rat reproduction study there was an
increase in placental weight in females at the high dose level of 170
ppm.  There was also a biologically significant increase in gestation
length in high dose F0 and F2 females (F1a and F3a intervals).  The NOEL
for endocrine effects is 70 ppm (3.5 mg/kg/day)>

<C. Aggregate Exposure>

<	1. Dietary exposure. Based on dietary, drinking water and
non-occupational exposure assessments, there is reasonable certainty of
no harm to the US population, any population subgroup, or infants and
children from chronic exposure to triflumizole.>

<	i. Food. Chronic dietary exposures were estimated utilizing the
Dietary Exposure Evaluation Model software with Food Commodity Intake
Database (DEEM-FCID), version 2.16.  EPA’s most recent estimate of
chronic estimated dietary exposures for triflumizole are reported in the
August 23, 2006, Federal Register notice which established emergency
exemption tolerances on a variety of crops.  In that assessment, EPA
used a mixture of anticipated residues (i.e., mean residues from field
trials) and tolerances for the different crops.  EPA included percent
crop treated information from the Biological and Economic Analysis
Division (BEAD) for apples, grapes and pears, while all others were
assumed to be 100% treated.  EPA used modified processing factors for
apples and grapes based on previously submitted studies, while default
processing factors were used for all other foods.  EPA also included an
estimated concentration in drinking water of 40 ppb, which is the
chronic (annual average) concentration in surface water generated by the
FIRST model, in the residue file for the August 23, 2006, assessment. 
Estimated chronic dietary exposures (including drinking water) in the
August 23, 2006, notice are reported as 17% of the cPAD for the general
U.S. population, 24% of the cPAD for all infants less than 1 year old,
and 31% of the cPAD for children aged 1-2 years old.  The cPAD used in
the August 23, 2006, notice is 0.015 mg/kg/d, so it is possible to
estimate the chronic exposures in terms of mg/kg/d by multiplying the %
cPAD estimates by the cPAD itself (0.015 mg/kg/d), as shown in Table 1. 
These exposure estimates form the baseline for the current assessment. 
The only the member of subgroup 5B not included in EPA’s assessment
were added to this risk assessment (cabbage (Chinese, bok choy) and rape
greens).  These crops were included in the current incremental chronic
exposure assessment using tolerance level residues and default
processing factors and assuming 100% crop treated.  Estimated chronic
exposure associated with these two additional subgroup 5B crops are
quite low:  0.000044 mg/kg/d for the general U.S. population, no
exposure for all infants, and 0.000030 mg/kg/d for children aged 1-2
years.  Finally, the resulting total chronic dietary exposures is
expressed as a percent of the revised cPAD (0.035 mg/kg/d).  Thus, the
total chronic dietary exposures are estimated to be 7.4% of the cPAD
(0.035 mg/kg/d) for the general U.S. population, 10% for all infants,
and 13% for children aged 1-2 years old.  Chronic dietary exposures
below 100% of the cPAD are reasonably anticipated to result in no harm
to exposed populations.  

For the acute assessment, EPA’s August 23, 2006, assessment assumed
tolerance-level residues, and 100% crop treated for all crops.  EPA used
modified processing factors for apples and grapes based on previously
submitted studies, while default processing factors were used for all
other foods.  Drinking water was included directly into the dietary
assessment using the acute (peak) concentration for surface water (191
ppb) estimated by the FIRST model.  For this updated assessment, an
acute residue file was created using all the information and assumptions
from the EPA assessment and then adding the remaining subgroup 5B crops
assuming tolerance-level residues, 100% crop treated and default
processing factors.  Acute exposures were calculated using DEEM-FCID
version 2.16.  The acute population adjusted dose (aPAD) for
triflumizole is 0.25 mg/kg/d for the general population and 0.1 mg/kg/d
for females aged 13-49.  At the 95th percentile, which is the
appropriate point of comparison for this conservative Tier 1 acute
dietary assessment, the estimated acute exposures range from 9.3% of the
aPAD for the general U.S. population to 25% of the aPAD for children
aged 1-2 years old.  For females aged 13-49 years old,  the 95th
percentile acute dietary exposure is 17% of the subpopulation-specific
aPAD (0.1 mg/kg/d).  Acute dietary exposures below 100% of the aPAD are
reasonably anticipated to result in no harm to exposed populations.>

<	ii. Drinking Food. Tier I screen models FIRST (First Index Reservoir
Screening Tool) and SCI-GRO (Screening Concentrations in Ground Water)
were used to predict estimates of triflumizole concentrations in surface
and groundwater, respectively.  Drinking water levels of comparison
(DWLOCs) were estimated and compared to drinking water estimated
concentrations (DWECs) using EPA standard operating procedures.  DWECs
were obtained from the August 23, 2006, EPA assessment.  The DWECs are
40 ppb for chronic exposures, and 191 ppb for acute exposures.  The
chronic DWLOCs are 98 ppb for toddlers, 324 ppb for adult females and
369 ppb for all adults.  The chronic and acute DWECs are below the
chronic and acute DWLOCs, respectively, for all population groups and
exposure durations.>

<	2. Non-dietary exposure.There are no registered or proposed uses for
application by homeowners. For the proposed residential uses, only
professional handlers would apply triflumizole to woody ornamentals
(trees, shrubs, vines). Triflumizole is not used or proposed for use on
lawns or turf. Therefore, residential exposure is not likely.>

<D. Cumulative Effects>

<	The potential for cumulative effects of triflumizole, an imidazole,
and other substances that have a common mechanism of toxicity was
considered.  The mammalian toxicity of triflumizole is well defined.  No
reliable information exists to indicate that toxic effects produced by
triflumizole would be cumulative with those of any other chemical
compounds.  Therefore, consideration of a common mechanism of toxicity
with other compounds is not appropriate.  Thus, only the potential risks
of triflumizole are considered in the aggregate exposure assessment.>

<E. Safety Determination>

<	1. U.S. population. i. Short-Term Risk.  The acute Population Adjusted
Dose (aPAD) of 0.0233 mg/kg/day and was 9.3% of the aPAD.  Acute dietary
exposure to children (1-2 yrs) was 0.0630 mg/kg/day and was 25.21% of
the aPAD.  Acute dietary exposure to females 13-49 yrs was
0.0167/kg/day, and was 16.7% of the aPAD.  The acute drinking water
level of concern (DWLOC) was calculated to be 658 ppb, and the
model-predicted acute EECs of 191 ppb for surface water and 0.12 ppb for
groundwater are less than this DWLOC.  Therefore, acute aggregate
exposure from triflumizole is not expected to exceed the aPAD.   

ii. Chronic Risk.  The chronic Population Adjusted Dose (cPAD) of  0.035
mg/kg bw/day was based on the NOAEL of 3.5 mg/kg/day from the rat
reproduction study,  a 100x uncertainty factor, and a 1x FQPA safety
factor. The chronic dietary exposure to the general U.S. population was
0.002594 mg/kg/day and was 7.4% of the cPAD.  The chronic dietary
exposure to children (1-2 yrs) was 0.0036 mg/kg/day and 10% of the cPAD.
 The chronic DWLOC was calculated  to be 160 ppb, and the
model-predicted chronic EECs of 40 ppb for surface water and 0.12 ppb
for groundwater are less than this DWLOC.  Therefore, chronic aggregate
exposure from triflumizole is not expected to exceed the cPAD.>

<	2. Infants and children. Acute dietary exposure to children (1-2 yrs)
was 0.0630 mg/kg/day and was 25.21% of the aPAD.  The chronic dietary
exposure to children (1-2 yrs) was 0.0036 mg/kg/day and 10% of the
cPAD.>

<F. International Tolerances>

<	Maximum Residue Limits have been established for Chinese cabbage, kale
and turnip greens in Japan at 1.0 ppm.>