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EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR PESTICIDE PETITIONS 

PUBLISHED IN THE FEDERAL REGISTER 

EPA Registration Division contact: PV Shah, 703-308-1846

Jeneil Biosurfactant Company

[IN-10852]

EPA has received a pesticide petition ([IN-10852]) from Technology Sciences Group Inc. 

(1150 18th Street, Suite 1000 Washington, DC 20036) on behalf of Jeneil Biosurfactant Company, 

400 N. Dekora Woods Blvd. Saukville, WI 53080 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.

(Options (pick one)

2. to establish an exemption from the requirement of a tolerance for

Isobutryic acid, CAS #79-31-2, 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 NA remove

1. Plant metabolism.

2. Analytical method. NA remove

3. Magnitude of residues. NA remove

B. Toxicological Profile The toxic effect of concern for isobutyric acid, as with many acids, is 

corrosivity at the site of contact, including skin and eyes. Isobutyric acid is an endogenous 
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chemical in humans, being an intermediate in the metabolism of several amino acids. It is also a 

natural component of many foods; therefore, adverse effects are not likely when residues of 

isobutyric acid from a pesticide are ingested.

To assess the toxicity of isobutyric acid, a number of peer-reviewed data sources were used, 

including the Joint FAO/WHO Expert Committee on Food Additives’ (JECFA’s) review of methylsubstituted saturated aliphatic branched-chain primary alcohols, aldehydes, and acids; the 

European Chemicals Agency (ECHA) dataset/dossier for isobutyric acid; the European Chemicals 

Bureau (ECB) IUCLID dataset on isobutyric acid; and the OECD’s HPV Screening Information 

Dataset report on isobutyric acid and on n-Butyric Acid/n-Butyric Anhydride Category. In 

addition, data on isobutanol were used to evaluate the subchronic toxicity of isobutyric acid, as 

these two are related structurally and metabolically in mammals. Isobutyric acid is a metabolic 

product of isobutanol. Isobutanol is metabolized by alcohol dehydrogenase to form isobutyric 

acid via conversion to isobutyraldehyde. The OECD (2003) and European Chemicals Agency 

(ECHA) also used this approach to assess isobutyric acid’s toxicity.

1. Acute toxicity. In an OECD test guideline (TG) 401 study, male and female WISW rats 

(5/sex/dose) received isobutyric acid (>99% pure) by gavage at doses of 1990, 2510, 2835, or 

3160 mg/kg bw, and were observed for 14 days. Observations included slight to severe sedation 

and ataxia, lateral and prone position, labored breathing, and staggering with the first 30 

minutes. After that time, animals exhibited hypothermia, ruffled fur, trembling, bloody noses 

and snouts, and blood in the urine. Signs persisted in some animals until the end of the 14-day 

observation period. There was clear body weight reduction even at the lowest dose of 1990 

mg/kg bw. Mortality was seen at all 4 doses (3/10, 8/10, 9/10, 8/10). The LD50 was determined 

to be 2230 mg/kg bw. Another OECD TG 401-equivalent study derived a similar oral LD50 value. 

Gassner rats were gavaged with 190, 1516, 2370, 2650, 3030 or 6060 mg/kg bw and observed 

for 7 days. Clinical signs of toxicity included abdominal position, apathy, dyspnea, cyanosis, 

acute dilatation, and proventiourlus septum; body weights were not tracked. Mortality was 

100% at the two high doses, and 80%, 20%, 0% and 0%, respectively, in the remaining doses. 

The oral LD50 was 2510 mg/kg bw. An older acute oral toxicity study of male Carworth-Wistar 

rats used gavage doses of 161-436 mg/kg bw and derived an LD50 of 266 mg/kg bw (ECHA 2013). 

JECFA references a secondary source of an oral rat study in which the LD50 was determined to be 

280 mg/kg. No further data were provided. In rabbits, the oral LD50 for isobutyric acid was 8000 

mg/kg bw.

Overall, acute oral LD50 values range from 266-2230 mg/L in rats. ECHA rated the study 

determining the LD50 of 2230 mg/kg bw as “reliable without restriction,” while the other two rat 

studies were determined “reliable with restrictions.” The two lower LD50 values may or may not 

reference the same original study. It is unclear why these values are so disparate from the other 

two values. Most of the details on the test material (e.g., purity, stability, storage conditions), 

the effects (e.g., necropsy and any other examinations), etc., were not available for review in 

the two studies with lower LD50 values. Based on the ECHA rating of the study with the higher 

LD50, oral Toxicity Category III is appropriate for isobutyric acid.
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An acute dermal study was conducted in New Zealand white male rabbits (4/group) in a study 

equivalent to an OECD Guideline study. Administration of the test compound at concentrations 

of 351 - 636 mg/kg and occlusive wrapping for 24 hours was followed by a 14-day observation 

period. The dermal LD50 was 475 mg/kg bw, corresponding to acute dermal toxicity category II.

No mortality was noted in an OECD guideline study, when 6 male and 6 female rats inhaled air 

saturated with isobutyric acid (about 9.59 mg/L) for eight hours. This corresponds to an acute 

inhalation toxicity category of IV.

2. Genotoxicty. Results for multiple Ames assays on isobutyric acid were negative for 

mutagenicity under all conditions tested. The Salmonella typhimurium strains that have been 

tested are TA98, TA100, TA1535, TA1537, and TA1538, and concentrations tested are as high as 

5000 μg/plate in the absence and presence of metabolic activation. Negative results were also 

obtained in the rec assay with Bacillus subtilis H17 and M45 at concentrations of 19 g/plate. 

Isobutyric acid at concentrations up to 1000 g/mL did not induce unscheduled DNA synthesis in 

rat hepatocytes. A mouse lymphoma assay produced weakly positive results in L5178Y TK+/-

cells at a concentration of 500 g/mL without metabolic activation, and negative results at 600 

g/mL in the presence of activation. JECFA concluded that isobutyric acid, along with other 

aliphatic acyclic branched-chain primary alcohols, aldehydes, and carboxylic acids are not 

mutagenic or clastogenic in vitro or in vivo. JECFA did not attribute the one weakly positive 

effect in the mouse lymphoma assay to direct DNA damage.

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 post-coitum 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 postinsemination 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.

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 
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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 (ECHA 2014b). The study was rated “reliable without restriction” by the European 

Chemicals Agency (ECHA).

4. Subchronic toxicity. There were no studies identified on the subchronic, chronic, 

developmental, or reproductive toxicity of isobutyric acid. A structural assessment of toxicity 

was carried out using the method of Cramer. Repeat-dose studies of isobutanol were used to 

bridge the subchronic data gap for isobutyric acid. Isobutanol is related structurally and 

metabolically to isobutyric acid. In animals, isobutanol is metabolized by alcohol dehydrogenase 

to isobutyric acid via conversion to isobutyraldehyde. 

The Joint FAO/WHO Expert Committee on Food Additives (JECFA) reviewed isobutyric acid as a 

member of the methyl-substituted saturated aliphatic branched-chain primary alcohols, 

aldehydes, and acids group, and determined that isobutyric acid and the other 21 compounds in 

this group belong in Cramer Structural Class I. The Cramer scheme is a peer-reviewed approach 

to classifying chemicals with respect to non-cancer risk from oral exposure. It primarily uses 

information on the toxicity of a chemical’s substructures and the predicted pathway of 

mammalian metabolism. Other factors in the classification include whether the compound 

occurs naturally in the body and in food. Isobutyric acid is categorized as a Class I substance, 

which is the lowest concern, based on the absence of substructures associated with toxicity, an 

efficient metabolic pathway, and the fact that it is an endogenous chemical in humans and in 

food. 

In a 90-day oral rodent toxicity study on isobutanol, which served as the scientific basis for US 

EPA’s oral Reference Dose (RfD) for that compound (U.S. EPA 1991), the test compound was 

administered to 30 Crj: CD(SD) rats/sex/dose by gavage 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 difference between dosed groups and 

controls were found for ophthalmoscopic examination, hematology, urinalysis, organ weights, 
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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 inhalation study, 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. During exposure time only, there was a slight decreased response to external 

stimuli that disappeared immediately after exposure. ECHA considered it an effect of the 

narcotic properties of isobutanol rather than an adverse effect. In high dose females, total 

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

0.05). ECHA 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, gross pathology, and histopathology. 

The NOAEL for repeat-dose effects including neurotoxicity was 2500 ppm. 

.

5. Chronic toxicity. No chronic studies were identified for isobutyric acid or its 

metabolites.

6. Animal metabolism. Branched-chain acyclic aliphatic acids in general are rapidly 

absorbed following an oral dose. The metabolism of isobutyric acid has been well studied in 

rodent models. The β-carbon undergoes oxidation to yield propionic acid, which is eventually 

fully metabolized via the fatty acid pathway or Kreb’s cycle. Increased methylmalonic acid and 

succinic acid have also been detected in urine following an oral dose of isobutyric acid.

In male Charles River CD rats, 75.4, 83.3, and 66.7% of gavage doses of 4, 40, or 400 mg/kg bw 

radio-labeled isobutyric acid, respectively, were exhaled as CO2 after 4-hours. After 48-hours, 

85-90% of the doses had been exhaled. Less than 5% of the dose was recovered in the urine and 

feces. There was no isobutyric acid in milk or peripheral blood of dairy cattle that had eaten 170 

mg/kg/day for 10 days.

Isobutyric acid was detected in the serum and plasma of fasted human subjects (n=6) at mean 

concentrations of 30.7 μg/dL and 143 μg/dL, respectively. It has also been detected in human 

feces..
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7. Metabolite toxicology. NA Remove

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

in the isobutyric acid 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, isobutyric acid 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 isobutyric acid was determined 

using methods to estimate chronic dietary exposure for a generic inert ingredient. This 

assessment considers drinking water and crop-specific residues from pre-harvest 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 sub-groups of the population using the Dietary Exposure Evaluation 

Model, DEEMTM. Assuming all crops are treated with formulated products containing 10% 

isobutyric acid by weight, the estimated chronic exposure for the total US population is 0.038

mg/kg/day, 10.1% of the chronic Population Adjusted Dose (cPAD). Children age 1 to 2 years old 

have the highest estimated exposure at 0.141 mg/kg/day, or 37.6% of the cPAD.

i. Food. Dietary exposures of concern are not anticipated for isobutyric acid due to its

lack of persistence in the environment and low general toxicity. A significant source of dietary 

isobutyric acid comes from natural food sources and its use as a food additive. The annual 

individual consumption of isobutyric acid from food flavoring substances was estimated to be 

140 μg/person/day in the U.S., equivalent to 2.0 μg/kg bw/day.

ii. Drinking water. Isobutyric acid exposure via drinking water from use as an inert 

ingredient is not expected to be significant. Isobutyric acid is readily biodegradable. Exposure 

via 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 

isobutyric acid due to its ready 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 
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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 isobutyric acid would be cumulative with those of any other chemical 

compounds. EPA has not made a common mechanism of toxicity finding as to isobutyric acid

and other compounds. Isobutyric acid 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 isobutyric acid 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 isobutyric acid, 

there is a reasonable certainty that no harm to any population subgroup will result from dietary 

and other nonoccupational exposures to isobutyric acid when used as an inert ingredient in an 

inert mixture intended for use in pesticide formulations. Adjusting for relative molecular 

weight, EPA’s oral RfD of 0.3 mg/kg/day for isobutanol was used to derive an RfD for isobutyric 

acid of 0.376 mg/kg/day, which added uncertainty factors totaling 1000 for interspecies 

extrapolation, intraspecies variability, and for extrapolating subchronic exposure to chronic 

exposure. The chronic Population Adjusted Dose (cPAD) was determined to be the same as the 

RfD because no effects of isobutanol on development or reproduction were observed, 

suggesting that isobutyric acid too would not increase susceptibility of sensitive populations. 

For the total US population, the estimated chronic dietary exposure from food and drinking 

water for isobutyric acid, calculated as 10% of all agricultural formulations, is 10.1% of the cPAD, 

well below any level of potential concern.

2. Infants and children. An evaluation of susceptibility and uncertainty issues associated 

with isobutyric acid has been performed and there is a reasonable certainty that no harm to 

infants and children will result from the use of isobutyric acid as an inert ingredient in pesticide 

products. The structurally similar and metabolically related compound isobutyl alcohol was not a 

developmental toxin to rats or rabbits following inhalation. 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. The estimated chronic dietary exposure 

from food and drinking water was highest (37.6% of cPAD) for children aged 1 to 2 years old. 

This estimated exposure to isobutyric acid is well below any level of potential concern. 

F. International Tolerances

NA Remove
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