EPA Registration Division contact: Andrew Ertman (703) 308-9367

Interregional Research Project Number 4 (IR-4)

PP #2E8107

EPA has received a pesticide petition (2E8107) from IR-4 Project, 500 College 

Road East, Suite 201W, 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, by establishing a tolerance for residues of the insecticide fenpropathrin, 

alpha-cyano-3-phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate in or on the 

following commodities and crop groups: Barley, grain at 0.04 parts per million 

(ppm); Barley, hay at 3.0 parts per million (ppm); Barley, straw at 2.0 parts per 

million (ppm); Vegetable, fruiting, group 8-10 at 1.0 parts per million (ppm); Fruit, 

citrus, group 10-10 at 2.0 parts per million (ppm); Fruit, pome, group 11-10 at 5.0

parts per million; Bushberry subgroup 13-07B at 3.0 parts per million (ppm); Fruit, 

vine climbing, except fuzzy kiwifruit, subgroup 13-07F at 5.0 parts per million 

(ppm); and Berry, low growing, subgroup 13-07G at 2.0 parts per million (ppm). 

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

established tolerances for residues of the insecticide fenpropathrin, alpha-cyano-3-

phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate in or on the following

commodities and crop groups: Vegetable, fruiting, Group 8; Fruit, citrus, group 10; 

Fruit, pome, group 11; Bushberry subgroup 13B; Juneberry; Salal; Grape; and 

Strawberry. 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.
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A. Residue Chemistry

1. Plant metabolism. The plant metabolism of fenpropathrin has been 

studied in five different crop plant species: Cotton, apple, tomato, cabbage, and bean. 

Each of the studies involved foliar treatment of the plants under either greenhouse or field 

conditions. In all studies the total toxic residue is best defined as parent, fenpropathrin. 

The primary metabolic pathway for fenpropathrin in plants is similar to that in mammals. 

There are no qualitatively unique plant metabolites.

2. Analytical method. Adequate analytical methodology is available to detect 

and quantify fenpropathrin at residue levels in numerous matrices. The methods use 

solvent extraction and partition and/or column chromatography clean-up steps, followed 

by separation and quantitation using capillary gas liquid chromatography (GLC) with 

FID. The extraction efficiency has been validated using radiocarbon samples from the 

plant and animal metabolism studies. The enforcement methods have been validated at 

independent laboratories and by EPA. The limit of quantification (LOQ) for 

fenpropathrin in raw agricultural commodity samples is usually 0.01 ppm.

3. Magnitude of residues. Residue data has been submitted for Barley and 

the requested tolerances are adequately supported.

B. Toxicological Profile

Additional toxicological studies have been completed and have been submitted to reduce 

the uncertainty factor associated with fenpropathrin.

1. Acute toxicity. An assessment of the toxic effects caused by fenpropathrin is 

discussed in III. A. and III. B. of the Federal Register dated September 23, 2005 (OPP2005-0133) (FRL-7738-7). 

2. Genotoxicty. An assessment of the toxic effects caused by fenpropathrin is 

discussed in III. A. and III. B. of the Federal Register dated September 23, 2005 (OPP2005-0133) (FRL-7738-7). 

3. Reproductive and developmental toxicity. An assessment of the toxic effects 

caused by fenpropathrin is discussed in III. A. and III. B. of the Federal Register dated 

September 23, 2005 (OPP-2005-0133) (FRL-7738-7). 

4. Subchronic toxicity. An assessment of the toxic effects caused by fenpropathrin 

is discussed in III. A. and III. B. of the Federal Register dated September 23, 2005 (OPP2005-0133) (FRL-7738-7). 

5. Chronic toxicity. An assessment of the toxic effects caused by fenpropathrin is 

discussed in III. A. and III. B. of the Federal Register dated September 23, 2005 (OPP2005-0133) (FRL-7738-7). 
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6. Animal metabolism. Four metabolites were found in the urine of rats 

dosed with alcohol labeled fenpropathrin. The major metabolites were the sulfate 

conjugate of 3-(4'-hydroxyphenoxy)benzoic acid and 3-phenoxybenzoic acid (22-44% 

and 3-9% of the administered dose, respectively). The major urinary metabolites of the 

acid-labeled fenpropathrin were TMPA-glucuronic acid and TMPA-CH2OH (11-26% 

and 6-10% of the administered dose, respectively). None of the parent chemical was 

found in urine.

The major elimination products in the feces included the parent chemical (13-34% of the 

administered dose) and four metabolites. The fecal metabolites (percentage of 

administered dose) included CH2OH-fenpropathrin (9-20%), 4'-OH-fenpropathrin (4-

11%), COOH-fenpropathrin (2-7%), and 4'-OH-CH2OH-fenpropathrin (2-7%). There are 

no qualitatively unique plant metabolites. The primary aglycones are identical in both 

plants and animals; the only difference is in the nature of the conjugating moieties 

employed.

7. Metabolite toxicology. The metabolism and potential toxicity of the small 

amounts of terminal plant metabolites have been tested on mammals. Glucoside 

conjugates of 3-phenoxy-benzyl alcohol and 3-phenoxybenzoic acid, administered orally 

to rats, were absorbed as the corresponding aglycones following cleavage of the 

glycoside linkage in the gut. Normal metabolic pathways rapidly and completely 

eliminated the free or reconjugated aglycones. The glucose conjugates of 3-

phenoxybenzyl alcohol and 3-phenoxy-benzoic acid are less toxic to mice than the 

corresponding aglycones.

8. Endocrine disruption. No special studies to investigate the potential for 

estrogenic or other endocrine effects of fenpropathrin have been performed. However, as 

referenced above (see toxicological profile), a large and detailed toxicology database 

exists for the compound including studies acceptable to the Agency in all required 

categories. These studies include evaluations of reproduction and reproductive toxicity 

and detailed pathology and histology of endocrine organs following repeated or longterm exposure. These studies are considered capable of revealing endocrine effects and 

no such effects were observed.

C. Aggregate Exposure

1. Dietary exposure. Chronic and acute dietary exposure analyses were 

performed for fenpropathrin using anticipated residues, and accounting for proportion of 

the crop treated. The crops included in the analyses are the raw agricultural commodities 

cottonseed, currants, peanuts, strawberries, soybeans, lingonberry, juneberry, salal, and 

grapes, and the crop groupings succulent shelled pea (6B), head and stem brassica (5A), 

fruiting vegetables (8), cucurbit vegetables (9), citrus fruits (10), bushberry (13B) and 

pome fruits (11); processed products from these crops; and the resulting secondary 

residues in meat, milk, and eggs. Soybeans (and soybean products) were entered into the 

analyses using tolerance-level residues and 1% of the crop treated for chronic

assessments, and 2% of the crop treated for acute assessments. Proportion of crop treated 

was assumed to be equal for all crops in a crop grouping.
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Based on the minimal dietary intake of olives and caneberries, the magnitude of uses 

currently registered, and current aPAD and cPAD levels, it is not necessary to complete 

an additional dietary analysis to include these uses. Also, additional toxicological studies 

have been completed and will be submitted to reduce the uncertainty factor associated 

with fenpropathrin. None of the studies lowered the endpoints utilized in the risk 

assessment. 

i. Food. a. Acute. Acute dietary exposure was calculated for the U.S. 

population, females (13+), males (20+ years) and five children 

subgroups. At the 99.9th percentile of exposure, the acute population 

adjusted dose (aPAD) of 0.06 milligrams/kilogram body weight/day 

(mg/kg bwt/day) is not exceeded.

 b. Chronic. Chronic dietary exposure was calculated for the U.S.

population and 25 population subgroups. Chronic dietary exposure 

was at or below 0.6% of the chronic population adjusted dose (cPAD) 

of 0.025 mg/kg bwt/day, with apples being the commodity 

contributing the most to chronic exposure. Generally speaking, the 

Agency has no cause for concern if total residue contribution for 

published and proposed tolerances is less than 100% of the cPAD.

ii. Drinking water. Since fenpropathrin is applied outdoors to growing 

agricultural crops, the potential exists for fenpropathrin to reach ground water or surface 

water that may be used for drinking water. To further quantify exposure from drinking 

water, potential surface water and ground water concentrations for fenpropathrin were 

estimated using First Index Reservoir Screening Tool (FIRST) and Screening 

Concentration in Groundwater (SCI-GROW) modeling. Use on citrus, the most intense 

field use, was modeled. SCI-GROW modeling indicated that fenpropathrin would not be 

detected in ground water. FIRST modeling of potential surface water concentrations of 

fenpropathrin yielded annual average parts per billion (0.833 ppb) and peak day (1.030 

ppb) concentrations. These estimated drinking water environmental concentrations 

(DWEC) could be used for chronic and acute exposures, respectively.

2. Non-dietary exposure. No endpoints of concern were identified by the 

Health Effects Division, Hazard Identification Assessment Review Committee for dermal 

or inhalation exposures of any duration. Thus, no risk assessment is needed.

D. Cumulative Effects

 EPA issued a Pyrethroid Cumulative Risk Assessment on October 4, 2011. 

The Assessment incorporates multiple high-end inputs and combines the highest 

exposures/risk estimates across all pathways in a deterministic fashion resulting in a 

screening level assessment which is highly conservative and health protective. This 

cumulative assessment considered all registered uses of pyrethrins/pyrethroids and 
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included exposure from food, drinking water and residential settings from the oral, 

dermal and inhalation routes of exposure. This screening level assessment supports the 

conclusion that cumulative estimated risks from existing pyrethrins/pyrethroid uses are 

not of concern. Further, there is sufficient room in the pyrethroid cumulative risk cup to 

support consideration of new pyrethroids (i.e., currently unregistered pyrethroid 

pesticides) and new uses of existing pyrethroids having similar toxicity profiles and use 

patterns to those in the Assessment.

E. Safety Determination

1. U.S. population. i. Acute. The potential acute exposure from food to the U.S. 

population and various non-child/infant population subgroups provide values well below 

the aPAD. In a conservative policy, the Agency has no cause for concern if total acute 

exposure calculated for the 99.9th percentile is less than 100% of the aPAD. Acute 

DWLOC values are not exceeded by modeled DWEC values. It can be concluded that 

there is a reasonable certainty that no harm will result to the overall U.S. population and 

many non-child/infant subgroups from aggregate, acute exposure to fenpropathrin 

residues.

 ii. Chronic. Using the dietary exposure assessment procedures, the calculated chronic 

dietary exposure resulting from residue exposure from existing and proposed uses of 

fenpropathrin is minimal. The estimated chronic dietary exposure from food for the 

overall U.S. population and many non-child/infant subgroups ranges from 0.6% (children

1-6 years old, 0.000155 mg/kg bwt/day) to 0.1% (several groups) of the cPAD. 

Generally, the Agency has no cause for concern if total residue contribution is less than 

100% of the cPAD. Chronic drinking water levels of concern (DWLOC) values are not 

exceeded by modeled drinking water estimated concentration (DWEC) values. It can be 

concluded that there is a reasonable certainty that no harm will result to the overall U.S. 

population and many non-child/infant subgroups from aggregate, chronic dietary 

exposure to fenpropathrin residues.

2. Infants and children. The estimated chronic dietary exposure from food to 

infant and child subgroups ranges from 0.6% children 1-6 years old, 0.000155 mg/kg 

bwt/day to 0.1% nursing infants, 0.000026 mg/kg bwt/day of the cPAD. Generally, the 

Agency has no cause for concern if total residue contribution is less than 100% of the 

cPAD. Chronic DWLOC values are not exceeded by modeled DWEC values. It can be 

concluded that there is a reasonable certainty that no harm will result to infant and child 

subgroups of the U.S. population from aggregate, chronic exposure to fenpropathrin 

residues.
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F. International Tolerances

The following are the existing Codex MRLs for Fenpropathrin:

There are small differences between the Section 408 tolerances and the Codex MRL 

values for secondary residues in animal products. These minor differences are mainly 

caused by differences in the methods used to calculate animal feed dietary exposure. The 

only substantial difference between the US tolerance and the Codex MRL value is for 

tomatoes. The JMPR reviewer required that the MRL exceed the highest field residue 

value rounded up to unit value. The EPA reviewer agreed with Valent that one set of field 

residue samples was possibly compromised by the presence of a high rate processing 

treatment nearby. High outliers were ignored, and the tolerance was set at 0.6 ppm.