EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR 

PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER 

Bayer CropScience

PP# 5F8380

EPA has received a pesticide petition (PP# 5F8380) from Bayer CropScience, 2 T.W. 

Alexander Drive, P.O. Box 12014, Research Triangle Park, NC 27709 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 tolerances and/or changing 

existing tolerances for residues of trifloxystrobin (Benzeneacetic acid, (E,E)-α-

(methoxyimino)-2-[[[[1-[3- (trifluoromethyl) phenyl]ethylidene]amino]oxy]methyl]-

methyl ester) and the free form of its acid metabolite CGA–321113 ((E,E)-

methoxyimino-[2-[1-(3-trifluoromethyl-phenyl)-ethylideneaminooxymethyl]-

phenyl]acetic acid) in or on the raw agricultural commodity cotton, undelinted seed, 

(Crop subgroup 20C at 0.5 parts per million (ppm), cotton, gin byproducts at 3 parts per 

million (ppm) and corn, field, forage at 8 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 metabolism of trifloxystrobin in plants (cucumbers, 

apples, wheat, sugar beets and peanuts) is well understood. Identified metabolic pathways 

are substantially similar in plants and animals (goat, rat and hen). EPA has determined 

that trifloxystrobin parent and its metabolite CGA-321113 are the residues of concern for 

purposes of tolerance setting and risk assessment.

2. Analytical method. A practical analytical methodology for detecting and 

measuring levels of trifloxystrobin in or on raw agricultural commodities has been 

submitted. The limit of detection (LOD) for each analyte of this method is 0.08 ng 

injected, and the limit of quantitation (LOQ) is 0.02 ppm. The method is based on crop 

specific cleanup procedures and determination by gas chromatography with nitrogenphosphorus detection. A newer analytical method is available employing identical 

solvent mixtures and solvent to matrix ratio (as the first method), deuterated internal 

standards, and liquid chromatography/mass spectrometry-mass spectrometry (LC/MSMS) with an electrospray interface, operated in the positive ion mode. The limits of 

detection (LOD) for total trifloxystrobin range from 0.003 ppm to 0.01 ppm, depending 

on the crops, and the limit of quantitation is 0.01 ppm.
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3. Magnitude of residues. Cotton: Foliar application: Twelve field trials were 

conducted to measure the magnitude of prothioconazole and trifloxystrobin residues in/on 

cotton (representative test system for Crop Subgroup 20C, Cottonseed) following three 

foliar applications of Proline 480 SC with Gem 500 SC Fungicide. For all applications, 

individual application rates ranged from 0.196 to 0.206 kg a.i./ha for prothioconazole 

(0.175 to 0.184 lb a.i./A) and from 0.137 to 0.146 kg a.i./ha for trifloxystrobin (0.123 to 

0.130 lb a.i./A). Intervals between applications ranged from 12 to 15 days, and 

applications were made when the cotton plants were between BBCH 65 and 89 (BBCH 

65: full flowering or “mid bloom”; BBCH 89: about 90% of bolls open). Total seasonal 

application rates ranged from 0.60 to 0.61 kg a.i./ha for prothioconazole (0.53 to 0.55 lb

a.i./A) and from 0.41 to 0.43 kg a.i./ha for trifloxystrobin (0.37 to 0.39 lb a.i./A). In the 

harvest trials, seed cotton samples were collected at 27 to 31-day pre-harvest intervals 

(PHI). In three decline trials, seed cotton samples were collected at PHIs of 23-to 26-, 

29- to 30-, 34- to 36-, 38- to 40-, and 43- to 44-day. Three trials (two decline and one 

harvest) were designated as stripper cotton trials to be harvested using stripper 

equipment. The HAFT total trifloxystrobin residues in/on cotton, undelinted seed

following three foliar broadcast applications at a target PHI of 30 days was 0.27 ppm, 

with a maximum residue of 0.27 ppm. The HAFT total trifloxystrobin residues in/on 

cotton, gin byproducts following three foliar broadcast applications at a target PHI of 

30 days was 0.99 ppm, with a maximum residue of 1.10 ppm.

Two field trials were also conducted to measure the magnitude of trifloxystrobin residues 

in/on cotton processed commodities following 3 foliar applications at a 5X rate (0.625 lbs 

ai/A). 

In-furrow application: Twelve field trials were conducted to measure the magnitude of 

trifloxystrobin residues in/on cotton (representative test system for Crop Subgroup 20C, 

Cottonseed) after a single in-furrow spray application at planting of trifloxystrobin 50 

WG Fungicide. The target application rate was 0.125 lbs a.i./A. The total trifloxystrobin 

residues were below the LOQ (<0.05 ppm) for all seed harvested at maturity. In two 

cotton processing trials, plots were treated at a 5X rate (283 g a.i./A). These trials yielded 

no detectable total trifloxystrobin residues (<0.05 ppm) in all samples analyzed (gin trash, 

undelinted seed and refined oil).

Corn: Three field trials were conducted to measure the magnitude of prothioconazole and 

trifloxystrobin residues in/on corn forage, grain, and stover at a target 0-day pre-harvest 

interval (PHI) for corn forage and a target 14-day PHI for corn grain and stover following 

applications of PROLINE SC4, Trilex 2.5 GAL, and GEM 500 SC FUNGICIDE via seed 

treatment, in-furrow application, and foliar spray applications. PROLINE SC4 is a 

suspension concentrate formulation containing 480 g prothioconazole per liter. Trilex 2.5 

GAL is a suspension concentrate formulation containing 240 g trifloxystrobin per liter, 

and GEM 500 SC FUNGICIDE is a suspension concentrate formulation containing 500 g 

trifloxystrobin per liter.

There was one control plot and four treated plots per trial. The first Treated plot received 

four foliar applications for the collection of forage at a PHI of zero days.
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The second treated plot received four foliar applications for the collection of stover and 

grain at a PHI of 14 days. The third treated plot received treated seed followed first by an 

in-furrow application at planting, then by three foliar applications for the collection of 

corn forage at a PHI of zero days. The fourth treated plot received treated seed followed 

first by an in-furrow application at planting, then by three foliar applications for the 

collection of corn stover and grain at a PHI of 14 days.

All applications were made with adjuvants (Induce, a non-ionic surfactant, at 0.125 

v/v%) using ground-based equipment. Duplicate composite samples of corn forage, grain, 

and stover from the treated plots, along with single untreated control samples, were 

collected at crop maturity; this corresponded to BBCH 85 for corn forage (BBCH85 = 

Dough stage; kernels yellowish to yellow) and BBCH 87–89 for corn grain and stover 

(BBCH 87 = Physiological maturity, black dot/layer visible at base of kernels; BBCH 89 

= Fully ripe; kernels hard and shiny).

The residues of trifloxystrobin (and its metabolite trifloxystrobin acid) were quantitated 

by high-pressure liquid chromatography/triple stage quadrupole mass spectrometry (LCMS/MS) using stable isotopically-labeled internal standards. The individual analyte 

residues (parent and metabolite) were summed to give a total residue. Residue 

measurements below the analyte LOQ were summed into the total residue value as the 

analyte LOQ value.

Freezer storage stability studies indicate that total trifloxystrobin residues would be stable 

in corn during frozen storage for at least 24 months. Corn forage, stover, and grain were 

held in frozen storage for a maximum of six months prior to extraction.

The "total" trifloxystrobin residues in corn treated with four foliar applications were as 

follows: field corn forage samples (collected at a nominal 0-day PHI) ranged from 2.35 

ppm to 7.43 ppm with a HAFT of 6.60 ppm. Field corn stover samples (collected at a 

nominal 14-day PHI) ranged from 0.30 ppm to 2.54 ppm with a HAFT of 2.35 ppm. 

There were no trifloxystrobin residues (<0.020 ppm) in any of the corn grain samples 

(collected at a nominal 14-day PHI). 

The "total" trifloxystrobin residues in corn treated with a combination of seed treatment, 

in-furrow and foliar applications were as follows: field corn forage samples (collected at 

a nominal 0-day PHI) ranged from 1.89 ppm to 5.99 ppm with a HAFT of 4.75 ppm. 

Field corn stover samples (collected at a nominal 14-day PHI) ranged from 0.42 ppm to 

3.29 ppm with a HAFT of 2.57 ppm. There were no trifloxystrobin residues (<0.020 

ppm) in any of the corn grain samples (collected at a nominal 14-day PHI). 

B. Toxicological Profile

1. Acute toxicity. There is a full battery of acute toxicity studies for 

trifloxystrobin. Trifloxystrobin is of mild acute toxicity by oral, dermal, or inhalation 

routes of exposure (Cat. IV), however it is a strong dermal sensitizer. Trifloxystrobin is a 

mild ocular (Cat III) and dermal irritant (Cat IV).
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2. Genotoxicty. No genotoxic activity is expected of trifloxystrobin under in-vivo

or physiological conditions. The compound has been tested for its potential to induce 

gene mutation and chromosomal changes in five different test systems. The only positive 

finding was seen in the in vitro test system (Chinese hamster V79 cells) as a slight 

increase in mutant frequency at a very narrow range (250 – 278 g/mL) of cytotoxic and 

precipitating concentrations (compound solubility in water was reported to be 0.61

g/mL; precipitate was visually noted in culture medium at 150 g/mL). The chemical 

was found to be non-mutagenic in the in vivo system or all other in vitro systems. 

Consequently, the limited gene mutation activity in the V79 cell line is considered a 

nonspecific effect under non-physiological in vitro conditions and not indicative of a real 

mutagenic hazard.

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

reductions in body weight gain and food consumption were observed in the dams at 100 

mg/kg/day. No teratogenic effects or any other effects were seen on pregnancy or fetal 

parameters except for the increased incidence of enlarged thymus at 1000 mg/kg/day. 

The developmental NOEL was 1000 mg/kg/day.

In the rabbit developmental study, body weight loss and reduced food 

consumption were observed in the dams at 50 mg/kg. No teratogenic effects or any other 

effects were seen on pregnancy or fetal parameters except for the increase in skeletal 

anomaly of fused sternebrae-3 and -4 at the top dose level of 500 mg/kg. This finding is 

regarded as a marginal effect on skeletal development that could have resulted from the 

40-65% lower food intake during treatment at this dose level. The developmental NOEL 

was 250 mg/kg.

In the 2-generation rat reproduction study, body weight gain and food 

consumption were decreased at 750 ppm (55.3 mg/kg/day), especially in females during 

lactation. Consequently, the reduced pup weight gain during lactation (750 ppm) and the 

slight delay in eye opening (1500 ppm) are judged to be a secondary effect of maternal 

toxicity. No other fetal effects or any reproductive changes were noted. The low 

developmental NOEL, 50 ppm (3.8 mg/kg) seen in this study was probably due to the 

lack of intermediate dose levels between 50 and 750 ppm. The reproductive NOAEL was 

1500 ppm (=110.6 mg/kg/day).

4. Subchronic toxicity. In a subchronic study in rats a NOAEL of 500 ppm (30.6-

32.8 mg/kg/day) was found based on decreased body weights (males), hypertrophy of 

hepatocytes (males), and pancreatic atrophy observed at the LOAEL of 2000 ppm (127-

133 mg/kg/day).

In mice, a NOAEL was determined at 500 ppm (76.9-110 mg/kg/day) based on increased 

liver weights and necrosis of hepatocytes observed at the LOAEL of 2000 ppm (315-425 

mg/kg/day).
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A subchronic feeding study in dogs resulted in a NOAEL = 30 mg/kg/day. Increased liver 

weight and hepatocyte hypertrophy in males were observed at the LOAEL of 150 

mg/kg/day. 

In a 28–day dermal toxicity study in rats the NOAEL was found at 100 mg/kg/day.

Increased liver and kidney weight were observed at the LOAEL of 1,000 mg/kg/day.

5. Chronic toxicity. A chronic feeding study in dogs established a no-observed 

adverse effect level (NOAEL) of 5 mg/kg bw/day. The lowest effect level (LOAEL) for 

this study was found at 50 mg/kg bw/day, based on clinical signs, increased liver weight 

and hepatocellular hypertrophy.

In a carcinogenicity study in mice liver effects were observed at doses of and above the 

LOAEL of 1000 ppm (131.1 mg/kg/day). The NOAEL was determined to be 300 ppm 

(39.4 mg/kg/day).

A chronic toxicity/carcinogenicity study in rats established a NOAEL of 250 ppm (9.81–

11.37 mg/kg/day). Decreased mean body weight and decreased mean body weight gain 

(compared to control) were observed at the LOAEL of 750 ppm (29.7–34.5 mg/kg/day).

The compound did not cause any treatment-related increase in general tumor incidence, 

any elevated incidence of rare tumors, or shortened time to the development of palpable 

or rapidly lethal tumors in the 18-month mouse and the 24-month rat studies. An ad hoc

subcommittee of the Cancer Assessment Review Committee on May 27, 1999

determined that trifloxystrobin should be classified as a "Not Likely Human Carcinogen," 

based on the lack of evidence for carcinogenicity in rats and mice. 

6. Animal metabolism. Trifloxystrobin is moderately absorbed from the 

gastrointestinal tract of rats and is rapidly distributed. Subsequent to a single oral dose, 

the half life of elimination is about 2 days and excretion is primarily via bile. 

Trifloxystrobin is extensively metabolized by the rat into about 35 metabolites, but the 

primary actions are on the methyl ester (hydrolysis into an acid), the methoxyimino group 

(O-demethylation), and the methyl side chain (oxidation to a primary alcohol). 

Metabolism is dose dependent as it was almost complete at low doses but only about 60% 

complete at high doses.

In the goat, elimination of orally administered trifloxystrobin is primarily via the feces. 

The major residues were the parent compound and the acid metabolite (CGA-321113) 

plus its conjugates. In the hen, trifloxystrobin is found as the major compound in tissues 

and in the excreta, but hydroxylation of the trifluormethyl-phenyl moiety and other 

transformations, including methyl ester hydrolysis and demethylation of the 

methoxyimino group, are also seen. In conclusion, the major pathways of metabolism in 

the rat, goat, and hen are the same.

7. Metabolite toxicology. Metabolism of trifloxystrobin has been well 

characterized in plants, soil, and animals. In plants and soil, photolytically induced 
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isomerization results in a few minor metabolites not seen in the rat; however, most of the 

applied materials remained as parent compound as shown in the apple and cucumber 

studies. All quantitatively major plant and/or soil metabolites were also seen in the rat. 

The toxicity of the major acid metabolite, CGA-321113 (formed by hydrolysis of the 

methyl ester), has been evaluated in cultured rat hepatocytes and found to be 20-times 

less cytotoxic than the parent compound. Additional toxicity studies were conducted for 

several minor metabolites seen uniquely in plants and/or soil. The studies indicate that 

these metabolites, including CGA-357261, CGA-373466, and NOA-414412, are not 

mutagenic to bacteria and are of low acute toxicity (LD50 >2000 mg/kg). In conclusion, 

the metabolism and toxicity profiles support the use of an analytical enforcement method 

that accounts for parent trifloxystrobin.

8. Endocrine disruption. Trifloxystrobin does not belong to a class of chemicals 

known for having adverse effects on the endocrine system. Developmental toxicity 

studies in rats and rabbits and reproduction study in rats gave no indication that 

trifloxystrobin might have any effects on endocrine function related to development and 

reproduction. The subchronic and chronic studies also showed no evidence of a long-term 

effect related to the endocrine system.

C. Aggregate Exposure

1. Dietary exposure. Assessments, using the DEEM FCID Version 4.02 software, 

were conducted to evaluate potential risks due to chronic and acute dietary exposure of 

the U.S. population and selected population subgroups to residues of trifloxystrobin. 

Consumption data used in this program were from NHANES WWEIA 2005-2010. These 

analyses cover all registered crops plus the previous proposed increase in tolerances to 

Crop Group 4A (leafy greens), 4B (leafy petioles), 5A (head and stem brassica), 5B 

(leafy brassica greens), 19A (herbs), and 19B (spices except black pepper), as well as, 

new proposed tolerance for cotton. EPA conducted a previous human health risk 

assessment on April 14, 2014 (D413712).

The EPA has established an acute Population Adjusted Dose (aPAD) of 2.5 mg/kg/day 

for acute dietary risk assessments based on a NOAEL of 250 mg/kg bw/day from a rabbit 

developmental toxicity study and an uncertainty factor or 100. The FQPA safety factor

was reduced to 1x based on toxicological considerations, the conservative residue 

assumptions used in the dietary exposure risk assessments, and the completeness of the 

residue chemistry and environmental fate databases. For chronic dietary analyses, the 

EPA established a chronic Population Adjusted Dose (cPAD) of 0.038 mg/kg/day based 

on a NOAEL of 3.8 mg/kg bw/day from the rat reproduction toxicity study and an 

uncertainty factor of 100. 

Results from the acute and chronic dietary exposure analyses described below 

demonstrate a reasonable certainty that no harm to the overall U.S. population or any 

population subgroup will result from the use of trifloxystrobin on currently registered 

uses plus the proposed changes tolerances. 
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i. Food. The unrefined acute assessment used 100% crop treated and tolerance 

level residue values. The refined chronic assessment used 100% crop treated, with both 

tolerance residue levels and average field trial residues for apple, grape, orange, and pear 

(as per previous EPA dietary assessment (D413712, 2014). Additional refinements were 

made using average residues for leafy greens (4A), leaf petioles (4B), head and stem 

brassica (5A), leafy brassic (5B), herb (19A), spice (19B), strawberry, and rice. Default 

processing factors were used for both acute and chronic dietary assessments. Acute 

exposure for food only, expressed at the 95th percentile of exposure, was 2.4% of the 

aPAD for Females 13-49 years old (only population subgroup of concern). The chronic 

exposure was 17% cPAD for the Total US Population and 43% cPAD for the most 

sensitive population, Children 1-2 years old.

ii. Drinking water. Estimated Drinking Water Concentrations (EDWCs) 

associated with trifloxystrobin use on all crops were calculated using PRZM-GW and 

PRZM-EXAMS to calculate ground water and surface water EDWCs, respectively. The

maximum acute and chronic ground water concentrations estimated by PRZM-GW were 

427 ppb and 365 ppb, respectively, and were higher than the surface water estimates

(EPA, 2014). The value from the highest PRZM-GW exposure scenarios were 

incorporated into the dietary risk assessment. The addition of the acute estimated 

drinking water concentration (EDWC) of 427 ppb resulted in 2.95% of the aPAD utilized 

for females 13-49 yrs. old. The addition of the chronic EDWC of 365 ppb utilized 36% 

of the cPAD for the US Population and 92% of the cPAD for Infants (<1 yr), the most 

highly exposed subpopulation. In conclusion, the results of the conservative acute and 

chronic dietary exposure analyses (including drinking water) are acceptable for all 

population subgroups examined. Therefore, there is a reasonable certainty that no harm 

will result from exposure to potential residues of trifloxystrobin in food and water.

2. Non-dietary exposure. The exposures from the proposed new uses are similar to

those exposures already registered for corn. As such, non-dietary exposures from these 

changes are covered by previous non-dietary risk assessments performed by EPA. As 

published in the Federal Register (FR Vol 68, no. 175, 10-Sep-03, FR Vol 73, no. 1, 

02-Jan-08), the EPA considered chronic, short term and intermediate term risk from 

residential uses of trifloxystrobin. The EPA determined that the risk did not exceed the 

Agency’s level of concern.

D. Cumulative Effects

EPA has determined, as published in the Federal Register (FR Vol 73, no. 1, 

02-Jan-08)), that unlike other pesticides for which EPA has followed a cumulative risk 

approach based on a common mechanism of toxicity, trifloxystrobin does not appear to 

produce a toxic metabolite produced by other substances. Therefore EPA has not 

assumed that trifloxystrobin has a common mechanism of toxicity with other substances.
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E. Safety Determination

1. U.S. population. Risk assessments for trifloxystrobin are based on a complete 

and reliable toxicity data package and highly conservative assumptions. Chronic 

aggregate dietary (food and water) exposure will utilize about 17% of the cPAD for the 

US Population. Acute aggregate dietary exposure (food and water) for the females 13-49 

yrs. old (the only population of concern) utilized 3% of the aPAD. Therefore, there is a 

reasonable certainty that no harm will occur to the US Population from aggregate 

exposure (food and drinking water) to residues of trifloxystrobin.

2. Infants and children. EPA has determined that the toxicology database for 

trifloxystrobin regarding potential pre- and post-natal effects in children is complete and 

does not indicate any particular developmental or reproductive concerns. The special 

FQPA SF has been reduced to 1X. Using the conservative assumptions described in the 

exposure section above, chronic dietary exposure to residues of trifloxystrobin in food 

and water for Infants (< 1 yr.) (the most highly exposed sub group) is less than 92% of

the cPAD. There is no acute endpoint of concern for children and infants. There are no 

non-dietary concerns for infants and children. Therefore, there is a reasonable certainty 

that no harm will occur to infants and children from aggregate exposure to residues of 

trifloxystrobin.

F. International Tolerances

International tolerances and CODEX tolerances for trifloxystrobin are established 

for many crops in various countries. No tolerances exist yet in Canada or Mexico for the 

new proposed uses.