Interregional Research Project No. 4

PP No. 2E8119

EPA has received a pesticide petition from Interregional Research Project #4 (IR4), Rutgers, The State University of New Jersey, 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 tolerances for residues of triflumizole [1-[1-((4-chloro-2-(trifluoromethyl) 

phenyl)imino)-2propoxyethyl]-1H-imidazole]] in or on the raw agricultural commodity 

tomato at 1.5 parts per million (ppm); fruit, pome, group 11-10 at 0.5 ppm; fruit, small, 

vine climbing, except fuzzy kiwifruit, subgroup 13-07F at 2.5 ppm; and berry, low 

growing, subgroup, 13-07G at 2.0 ppm; and amending the existing tolerance for 

vegetable cucurbit, group 9 from 0.5 ppm to 0.80 ppm.

IR-4 also proposed, upon the approval of the aforementioned tolerances, to 

remove established tolerances for apple at 0.5 ppm; pear at 0.5 ppm; grape at 2.5 ppm; 

and strawberry at 2.0 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 supports 

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-

(4chloro-2trifluoromethylphenyl)-n-propoxyacetamidine (FM-6-1), N-(4-chloro-2-

trifluoromethylphenyl)-n-propoxyacetanilide (FD-1-1) and the free or conjugated 

products of N-(4-chloro-2-trifluoromethylphenyl)-hydroxyacetamidine (the 0-

dealkylation product of FM-6-1), N-(4-chloro-2-trifluoromethylphenyl)-

hydroxyacetanilide (FD-2-1) and the triflumizole aniline (FA-1-1).

2. Animal metabolism. In livestock, oral administration of [14C]-triflumizole was 

conducted twice daily for 5 days at 14 mg/kg/day (equivalent to 280 ppm in feed for the 

cow) and 144 mg/kg/day (equivalent to 50 ppm in feed for chicken). On the sixth day the 

animals were sacrificed and meat, milk and egg samples were analyzed. Cow’s liver, 

kidney, fat and muscle contained 11.26, 3.36, 0.66, and 0.30 ppm of [14C]-triflumizole 

equivalent, respectively. Residues in milk reached a plateau of about 0.7 ppm after 24 

hours. Chicken liver, kidney, fat, and muscle contained 1.10, 0.74, 0.17 and 0.05 ppm of

[

14C]-triflumizole equivalent, respectively. Residues in eggs reach a maximum of 0.30 

ppm level. Metabolites identified in these tissues were mainly triflumizole aniline (FA-1-

1) and the sulfate/glucuronide conjugates of the 6-hydroxy derivative of triflumizole 

aniline (FA-1-5). The latter was the major metabolite in milk. Unchanged triflumizole 

was present in trace amounts in the whole egg.

3. 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 gas chromatograph equipped with nitrogen phosphorus 

detector, electron capture detector or mass spectrometry detection. The limit of 

quantitation of the method has been determined in the range of 0.01 ppm to 0.05 ppm for 

the combined residues of triflumizole and FA-1-1. The enforcement methodology has 

been submitted to the Food & Drug Administration for publication in the Pesticide 

Analytical Manual, Vol. II (PAM II).

4. Magnitude of residues. Magnitude of residue data were collected from four 

greenhouse trials located in the EPA Regions 2, 3, 6 and 9 to support the minor use of 

triflumizole on greenhouse cucumber for the control of powdery mildew. Foliar directed 

applications were used at all greenhouse sites at a targeted 0.25 lb a.i./A. Foliar directed 

applications for all trials were made at 6 to 8 day intervals. The last application was on 

the day of harvest (0 day PHI) at all trials. A decline study was conducted at one location, 

with the last application 0, 3, 7, 12 and 15 days before harvest (0-15 day PHI). The 

results from these trials show that the maximum residue of triflumizole (total) in 

greenhouse cucumber at 0 day PHI was 0.27 ppm. Residues of triflumizole (total) in the 

decline trial generally declined from the 0 day sampling (maximum residue of 0.10 ppm) 

to the 15 day sampling (maximum residue of <0.10 ppm). Residues detected in all control 

samples were analyzed and found to be <0.10 ppm in triflumizole (total).

Magnitude of residue data have been collected from four greenhouse trials located in 

NAFTA Regions to support the minor use of triflumizole on greenhouse tomato for the 

control of powdery mildew. At the three of the trials, four foliar directed applications of 

the test substance 6-8 days apart were made to the treated plots. At one trial, five 

applications of the test substance were made 6-14 days apart. The application rates 

ranged from 0.230 to 0.258 lb a.i./A per application for a total rate range of 0.921 to 

1.284 lb a.i./A per season. At all the field trials, samples were harvested 0 days after the 

last application. Additionally, at one trial, duplicate samples were collected 1, 4, 8, 10 

and 15 days after the last application. The total residues of triflumizole ranged from 

<0.50 to 0.88 ppm in samples taken at 0 days PHI. There were no residues above the 

lowest level of method validation of 0.50 ppm for samples taken at 1, 4, 8, 10 or 15 days 

PHI.

The nature of the residues of triflumizole is adequately understood in greenhouse 

cucumber and greenhouse tomatoes, and an acceptable analytical method is available for 

enforcement purposes. 

B. Toxicological Profile

1. Acute toxicity. The database includes the following studies for triflumizole 

technical: a rat acute oral study with a LD50 of 1.42 g/kg; a rabbit acute dermal study 

with a LD50 >5 g/kg; a rat acute inhalation study with LC50 >3.2 mg/l; a rabbit primary 

ocular irritation study which showed mild 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/Terraguard 480SC: a rat acute oral study with a LD50 >2 g/kg; a rabbit 

acute dermal study with a LD50 >5 g/kg; a rat acute inhalation study with a LC50 >3.3 

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.
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 rat hepatocytes, chromosome 

aberration assay in Chinese hamster lung (CHL) cells and a mouse micronucleus assay.

3. Reproductive and developmental toxicity. In a developmental toxicity study in 

rats, 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 effect level (NOEL) for maternal and 

developmental toxicity was 10 mg/kg/day. In another study Triflumizole was 

administered by oral gavage to pregnant, female New Zealand White rabbits at dosage 

levels of 0, 5, 25, or 50 mg/kg/day. Maternal toxicity was observed at a dose level of 50 

mg/kg/day as demonstrated by a reduction in body weight gain. There were no 

developmental or teratogenic effects. The NOEL for maternal toxicity was 25/mg/kg/day 

and the NOEL for developmental toxicity was greater than 50 mg/kg/day. The 

reproductive toxicity of triflumizole was evaluated in 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 Flb, 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. Critical review of the 

gestation length data demonstrated that the NOEL for reproductive effects in this study is 

70 ppm (MRID # 47136402), 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 (3.5 mg/kg/day) 

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 6 hours per day for 

three weeks at dose levels of 10, 100 and 1000 mg/kg/day. Female rats exposed to 1000 

mg/kg/day exhibited mild fatty vacuolation in the liver, which was within the range of 

normal biological variation. Therefore, the no-observed effect level (NOEL) for 

subchronic dermal toxicity in rats was considered to be greater than 1000 mg/kg/day.

In a subchronic feeding study in rats 80 male and 80 female SD rats were administered 

triflumizole at dose levels of 20,200, and 2000 ppm for 13-weeks. No remarkable clinical 

signs were seen. Histopathological findings indicated accumulation of fat droplets in the 

peripheral zone of the liver at dose levels of 2000 ppm. From this data, it is concluded 

that the target organ is the liver and the NOEL is considered to be 200 ppm. In another 

subchronic study in mice, 80 male and 80 female ICR mice were given diets containing 

0, 20, 200, and 2000 ppm of triflumizole for 13-weeks. No marked clinical signs were 

seen in the dosed groups except for growth retardation in males of 20 and 2000 ppm 

groups. A significant increase in liver weight was found in both sexes of the 2000 ppm 

groups. Histopathological findings showed that the dose-related change was confined to 

the males in the 2000 ppm group. The lesion consisted of swollen liver cells in the central 

zone. The NOEL was determined to be 200 ppm.

Four-week cumulative toxicity study was conducted in rats and mice at dose levels of 0, 

20, 200, 2000 ppm. No marked clinical signs of toxicity were seen. Liver weights and 
body weight ratios were elevated in both sexes at 2000 ppm dose levels. 

Histopathological findings were confined to hepatic lesions in males of the 2000 ppm 

group, with swollen cells in the central zone. The target organ was liver and the NOEL 

was determined to be 200 ppm. 

Neurotoxicity testing battery included acute and subchronic neurotoxicity studies. In the 

acute neurotoxicity study 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. In a 90 day neurotoxicity Study male and 

female rats were administered triflumizole in the diet at dose 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 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 (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 in 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.

An immunotoxicity study was conducted to determine if triflumizole was immunotoxic 

by measuring antibody production to sheep red blood cells (SRBC) and natural killer 

(NK) cell activity in BALB/c female mice treated for 28-days with 0, 20, 200, and 2000 

ppm triflumizole. There were no effects of triflumizole, at any dose on thymus weight, 

spleen weight, or NK cytolytic activity, as a measure of innate immunotoxicity. 

Triflumizole at 20 and 200 ppm had no effect on terminal body weight or SRBC IgM 

production. Treatment with 2000 ppm triflumizole caused a small reduction in terminal 

body weight, and reduced anti-SRBC IgM production (0.55x of vehicle). In conclusion, 

the triflumizole NOAEL in this study was 200 ppm, and the LEL was 2000 ppm.

5. Chronic toxicity. In one year dog feeding study, 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 NOEL for chronic 

toxicity in dogs was 300 ppm (7.5 mg/kg/day). 

In a two-year rat feeding study, 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 of 1600 ppm there was a substantial reduction in 

body weight gain in males and females. At the mid and high dose levels of 400 and 1600 

ppm there was an increase in liver weight. 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 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. No evidence of oncogenic effects was demonstrated in rats. 

The dietary level of 100 ppm (5 mg/kg/day) is considered to be a NOEL. 

In two-year mouse oncogenicity study, triflumizole was fed to male and female B6C3F1 
mice for two years at dietary concentrations of 100, 400 and 1,600 ppm. At a dosage 

level of 1,600 ppm there was a substantial effect on body weight gain in males and an 

increase in liver weight in males and females. There was no evidence of oncogenic 

effects in mice as a result of triflumizole administration.

6. Animal metabolism. Triflumizole, [14C-Phenyl] 1-(1-((4-chloro-2-

trifluoromethylphenyl)imino)-2-propoxyethyl)-1H-imidazole, 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 the fungicide in 

mammals. The elimination of the imidazole ring yielded initially N-(4-chloro-2-

trifluoromethylphenyl)-n-propoxyacetamidine (FM-6-1), and N-(4-chloro2trifluoromethyphenyl-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. Based on available studies there are no endocrine effects 

of concern.

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 acute or chronic exposure to 

triflumizole.

i. Food. Tolerance level residues were used for the proposed commodities in the 

acute and chronic assessment. For the chronic assessment, ARs calculated as the mean 

value from field trial data were used, and the crops were assumed to be 100% treated for 

the new uses. For existing registered crops, percent crop treated were used, as listed in the 

June 3, 2009 Federal Register (Vol. 74, No. 105, 26536-26543). Chronic dietary 

exposures were estimated utilizing Dietary Exposure Evaluation Model software with 

Food Commodity Intake Database (DEEM-FCID), version 3.12, which incorporates 

NHANES 2-day food consumption data for 2003 – 2008. The updated version also uses 

food translations based on the EPA/USDA FCID recipe set as of March 2011. The 

revised cPAD of 0.0117 mg/kg/day was used in this assessment. The total chronic dietary 

exposures are estimated to be 67.2% of the cPAD for the general US population, 11.8% 

for all infants, 66.8% for children aged 1-2 years old, and 74.3% for children aged 3-5 

years old. Chronic dietary exposures below 100% of the cPAD are reasonably 

anticipated to result in no harm to exposed populations. 

Acute exposures were calculated using DEEM-FCID version 3.15. The acute population 

adjusted dose (aPAD) for triflumizole is 0.25 mg/kg/day for the general population and 

0.1 mg/kg/day 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 exposure range from 4.3% of the aPAD for all infants to 27.7% of the aPAD for 
children aged 1-2 years old, and 28.7% for children aged 3–5 years old. For females aged 

13-49 years old, the 95th percentile acute dietary exposure is 24.5%. Acute dietary 

exposures below 100% of the aPAD are reasonably anticipated to result in no harm to the 

exposed populations.

ii. Drinking Water. 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, obtained from the March 17, 2009, EPA’s acute exposures from the 

use on cherries, was estimated to reach a maximum of 37.4 ug/L. The chronic drinking 

water concentration was not expected to reach 16 ug/L . 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

U.S. population.

i. Short-Term Risk. The acute population adjusted dose (aPAD) for 

triflumizole is 0.25 mg/kg/day for the general population and 0.1 mg/kg/day for females 

aged 13-49. Acute dietary exposure to children (1-2 yrs) was 0.06922 mg/kg/day and 

was 27.7% of the aPAD. Acute dietary exposure to children (3-5 yrs) was 0.07162 

mg/kg and was 28.7% of the aPAD. Acute dietary exposure to females 13-49 yrs was 

0.06115 mg/kg/day, and was 24.5% of the aPAD. Therefore, acute aggregate exposure 

from triflumizole is not expected to exceed the aPAD.

ii. Chronic Risk. In the August 23, 2006, Federal Register Notice, EPA used a 

cPAD of 0.015 mg/kg/day. Since that time, Chemtura has resubmitted documentation 

supporting a revised cPAD for Triflumizole of 0.035 mg/kg/day (MRID# 47136402). The 

chronic Population Adjusted Dose (cPAD) of 0.035 mg/kg bw/day was based on the 

NOEL of 3.5 mg/kg/day from the rat reproduction study, a 100x uncertainty factor, and a 

1x FQPA safety factor. However, in the 2009 HED evaluation (EPA-HQ-OPP-2007-

0312-0008), EPA reset the FQPA safety factor to 3x, due to the lack of a NOAEL in the 

critical study. Therefore, the cPAD of 0.0117 mg/kg/day was used in this assessment. 

The chronic dietary exposure to the general U.S. population was 0.007865 mg/kg/day and 
was 67.2% of the cPAD. The chronic dietary exposure to children (1-2 yrs) was 0.007812

mg/kg/day and 66.8% 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 3.11 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 

0.0692 mg/kg/day and was 27.7% of the aPAD. The chronic dietary exposure to children 

(3-5 yrs) was 0.008693 mg/kg/day and 74.3% of the cPAD.

F. International Tolerances

No Codex MRLs have been established for the requested uses. Canada has 

established an MRL of 0.01 ppm for dried shelled pea and bean, except soybean (Crop 

Subgroup 6C); cereal grains (Crop Group 15, except rice; dry soybeans and peanuts. 

Ipconazole is currently registered in Argentina, Australia, Belarus, Bolivia, Bulgaria, 

Canada, China, Czech Republic, France, Hungary, Italy, Japan, Kazakhstan, Mexico, 

Moldova, Poland, Romania, Russian Federation, Ukraine, United Kingdom, Uruguay and 

the United States.