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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

INSTRUCTIONS: Please utilize this outline in preparing the pesticide petition. In 

cases where the outline element does not apply, please insert “NA-Remove” and 

maintain the outline. Please do not change the margins, font, or format in your 

pesticide petition. Simply replace the instructions that appear in green, i.e., “[insert 

company name],” with the information specific to your action.

TEMPLATE:

Bayer Healthcare LLC, Animal Health Division

IN-10838

EPA has received a pesticide petition (IN-10838) from Bayer Healthcare, LLC, 

Animal Health Division, P.O Box 390 Shawnee Mission, KS 66201, 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 to establish an exemption from the requirement of a 

tolerance for di-N-butyl adipate (DNBA, CAS # 105-99-7) under 40 CFR 180.910 when 

used in plastic container strips containing pesticides that are placed at the entrance to bee 

hives intended to control varroa mites.

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

B. Toxicological Profile

1. Acute toxicity. DNBA is low in toxicity following acute exposure, with an oral 

LD50 in rats of 1.52 g/kg body weight. An 8-hour inhalation exposure to air saturated 

with DNBA caused no deaths in a group of 6 albino rats. DNBA was not toxic to rabbits 

by the dermal route, with a dermal LD50 of 19.24 g/kg. DNBA is a dermal irritant. Eye 

irritation studies in rabbits indicated minor eye irritation with recovery in a few days. 

DNBA is not a dermal sensitizer in guinea pigs.

2. Genotoxicty. In two separate Ames Assays, no mutations were induced in any 

bacterial strain at any concentration of DNBA with or without metabolic activation. A 

chromosomal aberration assay was conducted on DNBA according to OECD Test 
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Guideline 473 using cultured Chinese Hamster lung (CHL/IU) cells. Structural 

chromosome aberrations were reported in this study with metabolic activation. In an in 

vivo micronucleus assay, no cytotoxic effects were identified in the bone marrow cells, 

and there was no significant increase in the number of cells with micronuclei at any dose 

or time after dosing.

3. Reproductive and developmental toxicity. In a reproduction study, Male and

female rats received DNBA at oral doses of 0,100, 300 and 1,000 mg/kg/day. There was 

no effect of DNBA exposure on any of the reproductive parameters measured. Pup body 

weight in the 1,000 mg/kg/day group was slightly reduced compared to controls at birth 

and on postnatal day 4. The authors identified the study NOAEL for general toxicity in 

the parental generation of 300 mg/kg/day based on the increase in kidney weights in 

males and females at 1,000 mg/kg/day. The NOAEL for reproduction in male and female 

rats was 1,000 mg/kg. The NOAEL for the F1 generation was 300 mg/kg/day.

In a developmental study, groups of 5 female rats received intraperitoneal (IP)

injections of DNBA on the 5th, 10th and 15th days of gestation. The dose levels were:

168 mg/kg, 504 mg/kg, 1,009 mg/kg, and 1,682 mg/kg. Four different control groups

were included in the study, one needle control and three groups that received different 

vehicles; the DNBA was administered neat with no vehicle. Dams were sacrificed on 

gestation day 20 and the numbers of corpra lutea, resorption sites, and dead and live 

fetuses were counted. Fetuses were evaluated for gross, skeletal antivisceral 

abnormalities. The NOAEL dose for developmental effects was 504 mg/kg based on a 

significant decrease in pup body weight compared to the needle control at the next 

highest dose of 1,009 mg/kg. No other significant adverse effects were reported at that 

LOAEL dose.

4. Subchronic toxicity. The potential effects of repeated oral exposure to DNBA 

were evaluated in Sprague-Dawley rats in a 28-day toxicity test. Male and female rats 

received gavage doses of DNBA of 0, 20,140, or 1000 mg/kg/day. No test substancerelated changes were seen in any of the monitored endpoints. The NOAEL in both

males and females was 1,000 mg/kg/day.

5. Chronic toxicity. The results of a predictive Quantitative Structure Activity

Relationship (QSAR) model indicate there is only a marginal concern that DNBP could

be an active carcinogen.

6. Animal metabolism. DNBA metabolism can be characterized based on the

common structural groups that make up DNBA, the known enzymes that interact with

these structural groups, and the metabolites that result from these interactions. DNBA is a 

linear fatty acid diester that has an n-butyl group bound to the oxygen atom on each end 

of the molecule. Given these structural groups, DNBA metabolism is catalyzed by 

carboxylesterase enzymes that are ubiquitous throughout the body, to produce butyl 

alcohol and adipic acid in a molar ratio of 1:2. N-butanol is metabolized by alcohol 

dehydrogenase, and adipic acid is metabolized by beta oxidation.
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7. Metabolite toxicology. Neither butyl alcohol or adipic acid is of toxicological

concern.

8. Endocrine disruption. Toxicity related to endocrine disruption was not

observed in the DNBA database.

C. Aggregate Exposure

1. Dietary exposure. The estimated chronic dietary exposure to DNBA was 

determined using the Dietary Exposure Evaluation Model (DEEM) software with the

Food Commodity Intake Database. The assessment assumes that the inert ingredient, is 

used on only honey from bee hives, that 100% of hives are treated with the inert, and 

100% of the inert is transferred to the honey. The maximum exposure was 0.2% of the 

Population Adjusted Dose.

i. Food. The food commodities included in the assessment were honey, and

honey, baby food.

ii. Drinking water. [No drinking water exposure from the use of DNBA in honey

bee hives to control varroa mites is expected.

2. Non-dietary exposure. The only non-dietary exposure to DNBA from use of the 

bee hive strips would be dermal exposure to workers that apply the strips to the hives if 

they do not wear gloves.

D. Cumulative Effects

DNBA has been used for many years in personal care products. DNBA is reported 

to be incorporated in suntan gels, creams and liquids at a concentration of 8%, and in nail 

enamel at 5%. The additional exposure to 0.2% of the population adjusted dose of DNBA 

is not expected to increase the current exposures significantly.

E. Safety Determination

1. U.S. population. The low toxicity of DNBA and the exaggerated dietary

exposure assessment suggest that the total aggregate exposures will be well below the 

acceptable exposure. Thus, a safety finding for DNBA can be concluded for aggregate 

exposures from dietary and non-dietary uses.

2. Infants and children. The low toxicity of DNBA and the exaggerated dietary 

exposure assessment suggest that the total aggregate exposures for infants and children 

will be well below the acceptable exposure. Thus, a safety finding for DNBA can be 

concluded for infant and child exposures from dietary uses.

F. International Tolerances NA-Remove
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