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EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR 

PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER 

EPA Registration Division contact: William Cutchin 703-305-7990 

Jeneil Biosurfactant Company

IN-10850

 EPA has received a pesticide petition (IN-10850) from Jeneil Biosurfactant 

Company, 400 N. Dekora Woods Blvd. Saukville, WI 53080 requesting, 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 to establish an exemption from the requirement of a 

tolerance for isobutyl isobutyrate, CAS #97-85-8,when used as an inert solvent applied to 

growing crops or harvested crops under 40 CFR 180.910 in pesticide formulations. 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. NA

 2. Analytical method. NA

 3. Magnitude of residues. NA

B. Toxicological Profile

 Isobutyl isobutyrate, which is a natural component of many fruits, essential oils, 

and fragrances, metabolizes readily to innocuous products. Therefore, oral toxicity 

resulting from the use of isobutyl isobutyrate as an inert ingredient in pesticides is not 

expected to be significant. To further evaluate the toxicity of isobutyl isobutyrate the 

OECD SIDS dataset on isobutyl isobutyrate was consulted. In addition, data on 

isobutanol from the US EPA's IRIS database is referenced. Isobutanol is one of the 

primary metabolic products of isobutyl isobutyrate, and therefore these data can be 

bridged to assess the toxicity of the ester. 

 1. Acute toxicity. Acute toxicity data categorize isobutyl isobutyrate into Acute 

Toxicity Category IV for oral, inhalation, and dermal exposure. The acute oral LD50 value 

in rats and mice was >6,400 mg/kg/bw. More recent studies of isobutanol, a metabolite of 

isobutyl isobutyrate, derived similarly high values for the acute oral median lethal dose, 
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around 3000 mg/kg/bw in rats. Acute inhalation toxicity is likewise low, with a 6-hour 

LC50 between 3.88 and 31.94 mg/L isobutyl isobutyrate in rats. The dermal LD50 value in 

guinea pigs was >8550 mg/kg/bw. 

 2. Genotoxicty. Isobutyl isobutyrate did not induce reverse mutations in 

Salmonella typhimurlum strains TA98, TAIOO, TA1535, and TA1537, or in Escherichia 

coli strain WP2 uvrA at concentrations as high as 5000 pg/mL in the absence or presence 

of metabolic activation. In vivo genotoxicity studies of isobutanol are all negative. 

 3. Reproductive and developmental toxicity. 

In two prenatal developmental toxicity inhalation studies, mated female Wistar 

rats and Himalayan rabbits were exposed to isobutanol (99.8%) at vapor concentrations 

of 0,151, 758 or 3030 ppm (0, 500, 2,500 or 10,000 mg/m3

) for six hours/day. The rats 

were dosed on postcoitum days 6-15. No mortality or significant differences in clinical 

signs, body weight development, or gross pathology between controls and treated groups 

were observed. No effects on development were noted. The maternal and developmental 

rat NOAELs were 3030 ppm. Rabbits (15/dose) were dosed on post-insemination days 7-

19. High-dose rabbit dams had a slightly lower body weight gain, particularly during the 

first phase of exposure. The maternal NOAEL for rabbits was 758 ppm. Fetuses exhibited 

no signs of developmental changes in response to isobutanol. Therefore, the rabbit 

developmental NOAEL was 3030 ppm, the highest dose (OECD 2004). 

Reproductive Toxicity 

In a 2-generation reproductive inhalation study isobutanol (99.9%) was 

administered to 30 Crl:CD(SD)IGS BR rats/sex/dose by whole body exposure at 0, 

500,1000 and 2500 ppm (0, 1476, 2952, and 7380 mg/m3

) for 6 hours per day 7 days per 

week. Exposure began at the commencement of the study for the F0 generation, and on 

postnatal day 28 for the F1 generation. It ended after weaning of the pups (F0 generation 

postnatal day 28, F1 generation postnatal day 21). For dams, exposure was discontinued 

after day 20 of gestation through lactation day 5. 

No exposure-related effects were observed on F0 and F1 parental survival or on F0 and 

F1 reproductive performance, body weights, food consumption and food efficiency in 

males or females. There were no significant spermatogenic or macroscopic findings, 

changes in primordial follicle or corpora lutea counts, changes in mean organ weights or 

histopathologic lesions in the F0 or F1 rats at any dose. Pup endpoints were not 

significant for either F1 or F2 generations, including survival, general physical condition, 

and mean body weights. There were no macroscopic findings, changes in mean organ 

weights, or maturation of F1 pups. The NOAEL of isobutanol for parental systemic, 

reproductive and neonatal toxicity is 2500 ppm (7380 mg/m3

the maximum applied dose) 

in males and females of the F0, F1 and F2 generations. The study was rated "reliable 

without restriction" by the European Chemicals Agency (ECHA). 

 4. Subchronic toxicity. Isobutyl isobutyrate (purity >98%) had a low toxicity 

profile in the one subchronic toxicity study identified: an 18-week oral gavage study in 
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rats. Wistar rats (15/sex/dose) received doses of 0, 10, 100, or 1,000 mg/kg bw/day. No 

lasting significant effects were noted in blood or urine parameters, histological 

examination, behavior, appearance, body weight, or food/water consumption. There were 

no significant changes in organ weights related to treatment of animals with isobutyl 

isobutyrate. The NOAEL was reported to be 1000 mg/kg/day. 

Studies of isobutanol, the metabolite produced rapidly from isobutyl isobutyrate, 

further support that isobutyl isobutyrate is low in toxicity. In a 90-day oral rodent toxicity 

study on isobutanol, which serves as the scientific basis for US EPA's RfD for that 

compound, the test compound was administered to 30 Sprague-Dawley (Crj: CD(SD)) 

rats/sex/dose by gavage for 90 days at dose levels of 0, 100, 316, or 1000 mg/kg bw/day. 

Treatment related effects were seen only at 1000 mg/kg bw/day, and included 

hypoactivity, which was significant during week one and decreased markedly after week 

4, and lower body weight gain (18% below that of control rats) in males during week one. 

Food consumption averages were below those of the controls for both males and females 

during weeks 1 and 2. Clinical signs and effects on body weight and food consumption 

were all transient and were considered as adaptive and therefore as not adverse. In 

addition, serum potassium levels were 11-15% lower in both sexes compared to controls 

on day 29, but group mean serum potassium concentrations were similar for treated and 

control groups at the final clinical pathologic evaluation. No other significant differences 

between dosed groups and controls were found for ophthalmoscopic examination, 

hematology, urinalysis, organ weights, gross pathology and histopathology. The NOEL 

was determined to be 316 mg/kg bw/day and the NOAEL was 1000 mg/kg/day. U.S. 

EPA derived an oral RfD of 0.3 mg/kg/day for isobutanol by applying uncertainty factors 

totaling 1000 to this NOEL. 

Wistar rats (10/sex/group) were exposed to isobutanol in drinking water at 

concentrations of 0, 1000, 4000, or 16,000 ppm, equivalent to approximately 0, 80, 340, 

or 1450 mg/kg bw/day isobutanol actually ingested. The 90-day study was carried out 

under OECD Test Guideline 408 and included full hematology, urinalysis, and 

ophthalmological endpoints as well as postsacrifice histological exam. Body weight, food 

and water consumption, and clinical signs of toxicity were monitored throughout the 

study. There were no significant dose-dependent signs of toxicity in any of these 

parameters. Study authors concluded that the NOAEL for isobutanol was the highest 

dose, 1450 mg/kg/day. 

In a 90-day guideline study (Guideline: 82-7, Subdivision F (Neurotoxicity 

Screening Battery)), 99% pure isobutanol was administered by dynamic whole-body 

exposure to 10-20 Sprague- Dawley rats/sex/dose at 0, 250, 1000, or 2500 ppm for 6 

hours per day, 5 days/week (~0.75, 3.0, 7.5 mg/L). In high dose females, total erythrocyte 

count, hemoglobin, and hematocrit were slightly elevated compared to controls (p < 

0.05). The European Chemicals Agency (ECHA), which reviewed the study, considered 

this to be not biologically significant. No differences were found in body weight, food 

consumption, ophthalmoscopic examination, clinical observation, clinical chemistry, 

neurobehavioral observations, organ weights, pathology, and histopathology. The 

NOAEL for repeat-dose effects was the highest dose 2500 ppm. 
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 5. Chronic toxicity. No chronic studies were identified for isobutyl or its 

metabolites. Based on negative results in genotoxicity assays and an extensive history of 

exposure to isobutyl isobutyrate, carcinogenic potential of this compound is likely to be 

low. 

 6. Animal metabolism. Esters of short-chain alcohols are hydrolyzed rapidly in the 

intestines, liver and kidneys of experimental animals and form an alcohol and carboxylic 

acids which in this case would be isobutanol and isobutyric acid. These are reactions of 

the carboxylesterases or esterases, which predominate in hepatocytes but are present in 

most tissues throughout the body, including small intestine, colon, kidney, trachea and 

lung. In male rats injected intravenously with isobutyl isobutyrate, the parent compound 

decreased rapidly in blood and was undetected after 166 seconds. The half-life was 

calculated at 11.1 seconds. Isobutanol and isobutyric acid levels increased rapidly, with 

the acid consistently higher than the alcohol, suggesting that the former is a metabolic 

product of the alcohol in addition to the parent compound. Isobutyric acid will be 

conjugated and excreted or will undergo β-oxidation in the fatty acid metabolic pathway. 

 7. Metabolite toxicology. NA

 8. Endocrine disruption. Toxicity data related to endocrine disruption were not 

identified in the isobutyl isobutyrate database. As the scientific knowledge develops, 

screening of additional compounds may be added to the Endocrine Disruptor Screening 

Program (EDSP). When additional screening and/or testing is conducted, isobutyl 

isobutyrate may be the focus of screening and/or testing to better characterize effects 

related to endocrine disruption. 

C. Aggregate Exposure

 1. Dietary exposure. The estimated dietary exposure to isobutyl isobutyrate was 

determined using methods to estimate chronic dietary exposure for a generic inert 

ingredient. This assessment considers drinking water and crop-specific residues from preharvest applications of agricultural insecticides, herbicides and fungicides, assuming the 

highest established tolerance level residue for each commodity. The assessment assumes 

that the inert ingredient is used on all crops. The inert ingredient is assumed to be present 

in all commodities treated with 57 of the most significant active ingredients at the 

maximum tolerance level as identified by the U.S. EPA for the default assessment. 

Chronic dietary exposure estimates were derived for the general US population and subgroups of the population using the Dietary Exposure Evaluation Model, DEEMTM. The 

inert ingredient is assumed to be in the formulation at a concentration of S0% for the 

default assessment. Chronic dietary exposure estimates were derived for the general US 

population and subgroups of the population. The estimated exposure for the total US 

population is 0.1893 mg/kg bw/day, or 1.89% of the cPAD. Children age 1 to 2 years old 

have the highest estimated exposure at 0.7062 mg/kg bw/day, or 7.06% of the cPAD. 

 i. Food. Dietary exposures of concern are not anticipated for isobutyl isobutyrate 

due to its lack of persistence in the environment and low general toxicity. A significant 

source of dietary isobutyl isobutyrate comes from natural food sources and its use as a 
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food additive, JECFA (1999) estimated that in the U.S. the consumption of isobutyrate 

esters of aliphatic acyclic primary alcohols with branched-chain aliphatic acyclic acids 

from food additives is equivalent to that from natural sources. JECFA (1999) further 

estimated the current levels of intake of isobutyl isobutyrate from its use as a food 

flavoring agent to be 2.3 ug/person/day in the U.S., equivalent to approximately 0.033 

pg/kg bw/day (0.000033 mg/kg/day). Residues from this compound's use as an inert 

pesticide ingredient will be minimal and, particularly in relation to background dietary 

consumption, not an important dietary source. 

 ii. Drinking water. Isobutyl isobutyrate exposure via drinking water from use as 

an inert ingredient is not expected to be significant. The physical and chemical properties 

of isobutyl isobutyrate indicate it will volatilize, readily biodegrade, and therefore not 

persist in the water environment. Exposure via the drinking water was estimated in the 

DEEM dietary exposure assessment assuming a concentration of 100 ppb. 

 2. Non-dietary exposure. Residential exposures of concern are not anticipated for 

isobutyl isobutyrate due to its inherent ability to biodegrade in the environment, low 

projected use-level in pesticides, and low general toxicity. 

D. Cumulative Effects

 Section 408(b)(2)(D) (9v) of the FFDCA requires that, when considering whether 

to establish, modify, or revoke a tolerance, the Agency consider "available information" 

concerning the cumulative effects of a particular pesticide's residues and "other 

substances that have a common mechanism of toxicity." To our knowledge there are no 

available data or other reliable information that suggests any toxic effects produced by 

isobutyl isobutyrate would be cumulative with those of any other chemical compounds. 

EPA has not made a common mechanism of toxicity finding as to isobutyl isobutyrate 

and other compounds, isobutyl isobutyrate does not produce toxic metabolites in common 

with other substances of potential concern. For the purpose of the tolerance exemption 

proposed, it is assumed that isobutyl isobutyrate does not share a common mechanism of 

toxicity with other substances 

E. Safety Determination

 1. U.S. population. Taking into consideration all available information on isobutyl 

isobutyrate, there is a reasonable certainty that no harm to any population subgroup will 

result from dietary and other nonoccupational exposures to isobutyl isobutyrate when 

used as an inert ingredient in an inert mixture intended for use in pesticide formulations. 

The toxicity profile of isobutyl isobutyrate indicates a low hazard from all routes of 

exposure, and a lack of genotoxicity. Isobutyl isobutyrate metabolizes rapidly and 

completely to isobutanol, which displays low repeat-dose toxicity and an absence of 

developmental and reproductive toxicity in two rodent species. The NOAEL of 1000 

mg/kg/day isobutyl isobutyrate derived by Drake et al. (1977) was considered to be the 

point of departure for this risk assessment. Although this was an older study, the high 

NOAEL is supported by studies of isobutanol, a primary metabolite of isobutyl 
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isobutyrate, indicating low toxicity for that compound too. Adjusting for uncertainty of 

inter- and intraspecies extrapolations (l0x each), the RfD for isobutyl isobutyrate was 

determined to be 1000/100 = 10 mg/kg/day. The chronic Population Adjusted Dose 

(cPAD) was considered equivalent to the RfD because no effects of isobutanol, on 

development or reproduction were observed, suggesting that isobutyl isobutyrate too 

would not increase susceptibility of sensitive populations. Therefore, the oral RfD and 

cPAD are both 10 mg/kg/day. For the total US population, the estimated chronic dietary 

exposure from food and drinking water for isobutyl isobutyrate, calculated as 50% of all 

agricultural formulations, is 1.89% of the cPAD, well below any level of potential 

concern. 

 2. Infants and children. There is a reasonable certainty that no harm to infants and 

children will result from the use of isobutyl isobutyrate as an inert ingredient in pesticide 

products. An evaluation of susceptibility and uncertainty Issues associated with isobutyl 

isobutyrate has been performed. The structurally similar and metabolically related 

compound isobutanol was not a developmental toxin to rats or rabbits following 

inhalation. Therefore, there is no concern for increased sensitivity to Infants and children 

to isobutyl isobutyrate when used as an inert ingredient in pesticide formulations. For this 

reason, a safety factor analysis has not been implemented to assess risk and the additional 

tenfold safety factor for the protection of infants and children is also unnecessary. 

F. International Tolerances

NA