i

EPA REGISTRATION DIVISION COMPANY NOTICE OF FILING FOR 

PESTICIDE PETITIONS PUBLISHED IN THE FEDERAL REGISTER 

EPA Registration Division contact: [PV Shah, (703) 308-1846] 

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: 

[Rhodia Inc.]

[Insert petition number]

 EPA has received a pesticide petition ([insert petition number]) from [Rhodia 

Inc., c/o SciReg, Inc.], [12733 Director’s Loop, Woodbridge, VA 22192] 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)

 1. by establishing a tolerance for residues of 

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

 [dimethyl esters of glutaric acid (CAS No. 1119-40-0), succinic acid (CAS No. 

106-65-0), and adipic acid (CAS No. 627-93-0), herein referred to as DME, under 40

CFR 180.910 when used as an inert ingredient 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. 

[This tolerance exemption petition summarizes and relies upon available data for 

DME; data for dibasic esters (DBE) under CAS No. 95481-62-2; and data on the 

individual components, dimethyl glutarate (DMG), dimethyl adipate (DMA), and 

dimethyl succinate (DMS). In addition, data on the metabolites, dicarboxylic acids 

(glutaric acid, succinic acid, and adipic acid), is included in this petition to support 

the toxicological profile of DME. Data from chronic and subchronic oral toxicity 

studies conducted with monosodium succinate is also presented. In the absence of 

experimental data on succinic acid, these studies conducted with monosodium 
2

succinate are considered a relevant surrogate as its most likely bioavailable form 

upon ingestion would be the succinic acid.] 

A. Residue Chemistry

 1. Plant metabolism.

 2. Analytical method. [Rhodia is requesting that DME be exempt from the 

requirement of a tolerance under 40 CFR 180.910. Therefore, Rhodia believes that 

an analytical method to determine residues in treated crops is not relevant.]

 3. Magnitude of residues. [Rhodia is requesting that DME be exempt from the 

requirement of a tolerance under 40 CFR 180.910. Therefore, Rhodia believes that 

data on the magnitude of residues in treated crops is not relevant.]

B. Toxicological Profile

 1. Acute toxicity. [Acute Oral Toxicity

DME was tested for acute oral toxicity in Sprague-Dawley rats, according to OECD 

Guideline No. 401 and in compliance with OECD Good Laboratory Practice. 

The test article, a liquid, was administered in a single oral dose at 2,000 mg/kg, at a 

dose volume of 1.835 mL/kg, to five males and five females. Examinations for 

mortality and clinical signs were performed daily during the 14-day study period. 

All surviving animals were euthanized and necropsied at the end of the observation 

period. 

No deaths occurred. The general behavior and body weight gain were not affected 

by treatment. No clinical signs were recorded during the study. At necropsy, a 

macroscopic examination revealed no abnormalities. Therefore, the oral LD50 for 

DME was greater than 2,000 mg/kg. 

Acute Dermal Toxicity

DME was tested for acute dermal toxicity in Sprague Dawley rats, according to 

OECD Guideline No. 402 and in compliance with OECD Good Laboratory Practice. 

The test article, a liquid (specific gravity: 1.09), was administered in a single dermal 

dose of 2,000 mg/kg, at a dose volume of 1.835 mL/kg to a clipped area of the skin (5 

x 7 cm) of five males and five females, for 24 hours under an semi-occlusive 

dressing. Examinations for mortality, clinical signs (with special attention given to 

the treatment sites), and body weight gain were performed during the 14-day study 

period. All surviving animals were euthanized and necropsied at the end of the 

observation period and subjected to macroscopic examination. 

No deaths occurred. No clinical signs were recorded during the observation period. 
3

No signs of dermal irritation were observed at the application site in any of the rats. 

The general behavior and body weight gain were not affected by treatment. At 

necropsy, a macroscopic examination revealed no abnormalities. Therefore, the 

acute dermal LD50 for DME was greater than 2,000 mg/kg. 

Primary Eye Irritation

DME was tested for acute ocular irritation with three male New-Zealand White 

rabbits, according to OECD Guideline No. 405 and in compliance with OECD Good 

Laboratory Practice. 

The test article, a liquid, was instilled in a single dose of 0.1 mL, into the 

conjunctival sac of the left eye of each animal. The right eye remained untreated 

and served as a control. The eyes were not rinsed. Ocular examinations were 

performed at 1, 24, 48, and 72 hours after instillation. 

A slight corneal opacity was observed on day 2 only (24 hours after instillation) in 

one of the animals. No iritis was observed throughout the observation period in any 

of the animals. Conjunctival redness was observed at 1 hour in all animals (score 2 

or 3), and in two animals on day 2 (score 1). Chemosis (score 1 or 3) was observed in 

two of three animals only at 1 hour after instillation. In addition, transient discharge 

was noted at 1 hour. All effects cleared by day 3 (48 hours after instillation). Based 

on the reported scores, the average eye irritation index was calculated to be 11 on 

day 1, and 3 on day 2. Therefore, with a maximum mean total score (MMTS) of 

11/110 on day 1 (1-hour after instillation) and full reversibility of the effects by day 

3, DME was considered minimally irritating in this study. 

Primary Dermal Irritation

DME was tested for acute skin irritation on three male New Zealand White rabbits 

according to OECD Guideline No. 404 and in compliance with OECD Good 

Laboratory Practice. 

The test article, a liquid, was applied as such on a dry compress, in a single dermal 

dose of 0.5 mL to a 6 cm2

 clipped area of the skin for four hours under a semiocclusive dressing. Cutaneous examinations were performed at 1, 24, 48, and 72 

hours after removal of dressing. 

No cutaneous reactions were observed in any of the animals, throughout the 

observation period. Therefore, DME is not considered a skin irritant. 

Dermal Sensitization

DME was assessed for skin sensitization potential in female CBA/CaOlaHsd mice, 

using the Local Lymph Node Assay, according to OECD Guideline No. 429 and in 

compliance with OECD Good Laboratory Practice. 
4

The test item was found soluble in the recommended vehicle acetone/olive oil (4/1, 

v/v) at the maximum concentration of 50% (w/v), and was also used undiluted 

(100%) as supplied. 

A preliminary test was conducted in two mice with the selected concentrations of 10, 

25, and 50% (w/v) and 100% (undiluted) to assess potential local irritation. After 24 

hours, no irritating effects were observed at these concentrations following a single 

application. The highest concentration retained for the main assay was therefore 

100% (undiluted). 

In the main assay, five treated groups of four animals each received the test item at 

the concentrations of 5, 10, 25, or 50% (w/v) prepared individually in the vehicle 

acetone/olive oil (4/1, v/v), or 100% (undiluted). One negative control group of four 

animals received the vehicle alone [acetone/olive oil (4/1, v/v)]. The positive control 

was assessed in a recent independent study, in which groups of four animals 

received the reference item α-Hexylcinnamaldehyde (HCA), a moderate sensitizer, 

at 5, 10, or 25% (w/v) in acetone/olive oil (4/1, v/v). 

During the induction phase, the test item, vehicle, or reference item was applied 

over the external surface of both ears (25 μl per ear) for three consecutive days (Day 

1, 2, and 3). After two days of resting, the proliferation of lymphocytes in the lymph 

node draining the application site was measured by incorporation of tritiated 

methyl-thymidine (3

H-TdR) on Day 6 following a single injection in the caudal vein 

of each animal of 250 μL of 77.01 μCi/ml 3H-TdR (i.e., 19.3 μCi; specific activity of 2 

Ci/mmol). The auricular lymph nodes were pooled for each experimental group. 

The measurement of dpm values were used to calculate stimulation indices [SI = 

(dpm treated group/dpm control group)]. 

No deaths occurred during the study period. No clinical signs were observed during 

the study. The body weights of the treated and control animals, recorded prior to 

the first application and prior to necropsy, were within the range commonly 

recorded for animals of the strain and age. 

On the second application day (Day 2), a slight to moderate ear erythema (grade 1 

or 2 on a scale of 4) was observed at both dosing sites in all mice of the two highest 

dose groups (50% and undiluted), persisting for a total of two days (Day 2 and 3). In 

addition, in those two groups, the size of the draining lymph nodes was obviously 

small compared to those of the control group. 

No significant lymphoproliferation was observed with the test substance at any of 

the doses (SI remained ≤ 1.0 in all treated groups). In contrast, a dose response and 

a significant lymphoproliferation at two doses were observed with the reference 

substance α-Hexylcinnamaldehyde. SI values were 2.4, 3.6, and 11.2 for 

concentrations of 5, 10, and 25% (w/v), respectively. 
5

Calculation of the EC3 value could not be performed for the test substance because 

no test concentration produced a stimulation index of 3 or higher. 

Under these experimental conditions, DME was not found to induce delayed contact 

hypersensitivity in the murine Local Lymph Node Assay.] 

 2. Genotoxicty. [Bacterial Reverse Mutation Test

The mutagenic potential of DBE was assessed in the Salmonella typhimurium Ames 

test. 

Salmonella typhimurium strains TA1535, TA1537, TA1538, TA98, and TA100 were 

tested in the presence and in the absence of metabolic activation system from liver 

fraction of rats (S9 mix) at doses up to 5000 μg/plate. 

The test substance, DBE, did not induce any noteworthy increases in the number of 

revertants which could be considered as relevant, either with or without S9 mix, in 

any of the five tester strains. 

In Vitro Mammalian Chromosome Aberration Test

The mutagenic potential of DBE was assessed in an in vitro mammalian 

chromosome aberration test according to OECD Guideline No. 473. 

Primary human lymphocytes were used in the presence and in the absence of 

metabolic activation system from liver fraction of Aroclor 1254-induced rats (S9 

mix). The test article was suspended in DMSO. Cells were exposed to 0.00%, 0.04%, 

0.10%, 0.3%, 0.4%, and 0.6 % (v/v), corresponding to 0.0, 0.44, 1.1, 3.3, 4.4, and 6.6 

mg/mL, respectively (samples in duplicate: one male and one female donor). Forty 

four to 47 hours after culture initiation, the medium was replaced with treatment 

medium and the cultures were incubated for three hours at 37°C and rinsed with 

Phosphate Buffered Saline (PBS). Fresh medium containing 5-bromodeoxyuridine 

(BrdU) was then added and incubation continued for 24 to 26 hours, with 

Colcemid® (0.1 ug/mL) present during the final two hours to arrest cells in 

metaphase. Cells were then harvested, slides prepared, stained (Giemsa), and 

evaluated. An additional confirmatory scoring was carried out in a different 

laboratory. Results were statistically analyzed. 

Negative and positive controls responded adequately. The study was therefore 

considered valid. 

Under non-activated conditions, DBE was cytotoxic at test concentrations above 

0.3% (v/v). DBE was somewhat more cytotoxic under activated conditions with 

significant cell cycle delay already at 0.3% (v/v). 
6

Under non-activated conditions, no statistically significant increases or 

concentration-related trends in chromosome aberrations were observed in either 

trial. Reduced mitotic indices at the higher DBE levels indicated that cytotoxic 

concentrations had been achieved. 

With S9 activation, statistically significant increases in the proportion of 

chromosomally-abnormal cells were seen at 0.3 and 0.4% DBE in Trial 1, and at 

0.4% DBE in Trial 2. Additionally, the proportion of cells having more than one 

aberration was significantly increased at the 0.4% level in Trial 1. In both trials, 

statistically significant concentration-related trends were seen in the proportion of 

abnormal cells (p < 0.001, Trials 1 and 2) and the proportion of cells with more than 

one aberration (p < 0.01, Trial 1; p < 0.05, Trial 2). Mitotic indices were markedly 

reduced at the higher test concentrations. Therefore, DBE exhibited clastogenic 

activity in human lymphocytes under S9 activated conditions. 

In Vivo Mammalian Erythrocyte Micronucleus Test

The mutagenic potential of DBE was assessed in a mouse bone marrow 

micronucleus test similar to OECD Guideline No. 474. 

Fifteen male and 15 female Cr1:CD®(ICR)BR mice per dose level were exposed 

nose-only to 0, 5.5, 11, or 19 mg/mL DBE in aerosol air once for six hours. 

Concurrent with the initiation of these exposures, five male and five female mice 

were dosed by intraperitoneal injection with 20 mg/kg cyclophosphamide, the 

positive indicator. The mice were observed for clinical signs of toxicity during and 

immediately following exposure. Surviving mice were weighed and observed daily 

until sacrifice. Approximately 24, 48, and 72 hours after initiation of exposure, five 

mice per sex per dose level were sacrificed by CO2 asphyxiation. 

Immediately following sacrifice, three bone marrow smear slides per animal were 

prepared. One thousand polychromatic erythrocytes (PCE) per animal were scored 

for the presence of micronuclei. The ratio of PCEs to normochromatic erythrocytes 

(NCE) was determined for each animal based on 1,000 total erythrocytes. 

While significant depression of the PCE to NCE ratios was seen in the 24-hour 11 

mg/L and 19 mg/L DBE-treated females, there were no statistically significant 

differences in the proportion of micronucleated PCEs between DBE-treated mice 

and the concurrent negative control groups at any sampling interval, and no 

statistically significant concentration-related trends were present. In comparison, 

both the cyclophosphamide-treated males and females showed significant increases 

in micronucleated PCEs compared to the concurrent air controls. Under the 

conditions of this assay, DBE did not induce micronuclei in bone marrow of mice. 

 
7

In Vivo Mammalian Erythrocyte Micronucleus Test

The potential induction of micronuclei by DMG in bone marrow cells of the Fischer 

344 rat was assessed according to OECD Guideline No. 474 (Mammalian 

Erythrocyte Micronucleus Test) and EPA Test Guideline OPPTS 870.5395 

(Mammalian Erythrocyte Micronucleus Test). 

Rats were treated for two six-hour periods of whole body inhalation exposure to the 

test substance at dose levels of 0.5, 1.0, and 2.0 mg/L expressed in terms of the 

weight of test substance per unit volume of chamber air. A positive control group 

was dosed orally, by gastric intubation, with cyclophosphamide at 20 mg/kg 

bodyweight. 

Incidences of weight loss were recorded throughout the test, but these were small 

and not considered to be significant. Clinical signs for animals treated with DMG 

included partially closed eyes, smacking mouth, lethargy, piloerection, oily fur, and 

brown staining around snout and jaws. No adverse clinical signs were noted for the 

negative control treated animals over the duration of the test. 

Bone marrow smears were obtained from five male and five female animals in the 

negative control and each of the test substance groups 24 hours after completion of 

the second exposure period and from the positive control group 24 hours after 

dosing. One smear from each animal was examined for the presence of micronuclei 

in 2,000 immature erythrocytes. The proportion of immature erythrocytes was 

assessed by examination of at least 1,000 erythrocytes from each animal. A record of 

the incidence of micronucleated mature erythrocytes was also kept. 

No statistically significant increases in the frequency of micronucleated immature 

erythrocytes and no substantial decrease in the proportion of immature 

erythrocytes were observed in rats treated with DMG. The positive control 

produced large, highly significant increases in the frequency of micronucleated 

immature erythrocytes. 

In conclusion, DMG did not show any evidence of causing chromosome damage or 

bone marrow cell toxicity when administered by whole body inhalation exposure in 

this in vivo test procedure. 

In Vivo Mammalian Chromosome Aberration Test

The mutagenic potential of adipic acid was assessed in an in vivo mammalian 

chromosome aberration test in Sprague-Dawley rats. In the acute tests, fifteen males 

per dose level were administered one dose of the test substance by oral gavage at 

dose levels of 0, 3.75, 37.5, or 375 mg/kg (Acute Test I) and 0 or 5000 mg/kg (Acute 

Test II). In the subacute tests, five males per dose level were administered five doses 

of the test substance 24 hours apart via oral gavage. The dose levels were 0, 3.75, 

37.5, or 375 mg/kg (Subacute Test I) and 0 or 2,500 mg/kg (Subacute Test II). Rats 
8

which had been given triethylene melamine (TEM) served as positive controls in the 

acute tests and rats given saline served as the negative controls for the acute and 

subacute tests. In the acute tests, animals were sacrificed at 6, 24, or 48 hours after 

administration of the test substance. In the subacute tests, animals were sacrificed 

six hours after the last dose. Four hours after the last test substance administration 

(2 hours prior to sacrifice) each animal was given 4 mg/kg of Colcemid® 

intraperitoneally in order to arrest the bone marrow cells in C-mitosis. At sacrifice, 

the bone marrow from one femur per animal was collected and processed to slide. 

The chromosomes of each cell were counted and only 50 diploid metaphase spreads 

per animal were analyzed for chromosomal aberrations. Mitotic indices were 

obtained by counting at least 500 cells. 

In the Acute Test I, neither the variety nor the number of aberrations differed 

significantly from the negative controls. The expected severe chromosomal damage 

was observed in the positive control group. The mitotic indices were within normal 

limits. In the Subacute Test I, the 37.5 mg/kg level contained one cell with a reunion 

and one cell that was polyploid, and the 375 mg/kg level contained three cells with 

breaks and one fragment. These were considered to be within normal limits of 

historical controls. The negative control group and the 3.75 mg/kg group contained 

no aberrations. In the Acute and Subacute Test II, neither the variety nor the 

number of aberrations differed significantly from negative controls. Therefore, no 

clastogenic effects above normal were observed in rats in vivo following a single 

oral dose of adipic acid or five consecutive doses.]

 3. Reproductive and developmental toxicity. [One-Generation Reproduction

Toxicity - rat

The effects of DBE on fertility were assessed by the inhalation route in a onegeneration study (equivalent to an OECD Guideline No. 415 study) in rats, exposed 

to test concentrations of 0, 0.16, 0.4, or 1.0 mg/L for 14 weeks pre-breeding, and for 

8 weeks through breeding, gestation and lactation. No relevant effects occurred in 

mating performance, fertility, gestation duration, litter size, development or 

viability, and lactation performance up to the highest concentration tested. A slight 

decrease in pup and parental weight was observed in the highest dose group. Gross 

pathology and organ weights in pups showed no noticeable changes. The NOEC for 

reproductive toxicity was therefore 1.0 mg/L. 

Developmental Toxicity - rat

DBE were tested in a developmental toxicity study on Crl:CD®BR rats after 

inhalation exposure using a protocol similar to OECD Guideline No. 414. 

Pregnant Crl:CD®BR rats (7-8 per group) were exposed to either 0.16, 0.4, or 1.0 

mg/L DBE by inhalation for six hours/day from Days 7 through 16 of gestation in 

whole-body inhalation chambers. A control group of pregnant rats was exposed 

simultaneously to air only. 
9

Parental examinations included clinical and cage side observations, body weight 

determination, and determination of feed consumption. Gross pathologic 

examination was performed on Day 21G and included counting of the corpora lutea 

and determination of number and position of all live, dead, and resorbed 

conceptuses in the uterus. Liver and gravid/empty uteri were weighed. All fetuses 

were weighed and examined for external alterations. About one-half of the live 

fetuses were examined for visceral alterations. All fetuses were sexed and examined 

for alterations of the skeleton after maceration. 

A suppression of both food consumption and the rate of body weight gain were seen 

in the 0.4 and 1.0 mg/L groups during the first six days of exposure. Staining on the 

fur and perineal area was seen in rats exposed to 1.0 mg/L and liver weight 

decreases, although not statistically significant, occurred in the two high exposure 

groups. None of the reproductive parameters were altered in any of the groups and 

no fetal effects were detected. 

 

It was concluded that DBE exert no adverse effect on prenatal development in the 

rat following inhalation exposures as high as 1.0 mg/L during the period of 

organogenesis. 

Developmental Toxicity - rabbit

DMG was administered by inhalation (whole-body, daily exposure, 6-hour/day) to 

groups of 22 mated Hra:(NZW)SPF rabbits. Animals were exposed on Gestation 

days 7 to 28. Target chamber concentrations were 0, 30, 100, 300, or 1,000 mg/m3. 

Maternal body weight, food consumption, and clinical observation data were 

recorded daily. Animals were euthanized on day 29 of gestation; dams were 

subjected to a gross external and internal postmortem examination. Gravid uteri 

were removed, weighed, and dissected and the uterine contents were described. 

Each live fetus was weighed, sexed, and examined for external, visceral, and skeletal 

alterations. 

At 1,000 mg/m3

, one animal was found dead on Gestation Day 13 and one animal 

was sacrificed in extremis on Gestation Day 22. Among survivors, there were 

compound-related reductions in maternal body weight gains and food consumption 

and there were compound-related clinical observations (ocular discharge and wet 

fur). At 300 mg/m3

, compound-related effects included reduced maternal body 

weight gains and increased clinical observations (ocular discharge). There was no 

evidence of compound-related maternal toxicity at 30 or 100 mg/m3

. 

Under the conditions of the study, there was no evidence of developmental toxicity 

at any level tested. Thus, the NOEC for maternal toxicity was considered to be 100 

mg/m3 and the NOEC for developmental toxicity was considered to be 1,000 mg/m3. 
10

Developmental Toxicity - rat

A developmental toxicity study was conducted with glutaric acid in CD® rats. 

Twenty five mated females per dose level were given daily oral doses via gavage of 

the test substance at 0, 125, 400, or 1,300 mg/kg on Gestation Days 6-15. Animals 

were observed daily for signs of toxicity and body weights were recorded 

periodically during gestation. On Gestation Day 20, the females were sacrificed and 

examined grossly. Reproductive status was determined. Corpora lutea, implantation 

sites, number of fetuses (live and dead), and resorptions (early and late) were 

recorded. All fetuses were weighed and examined externally. Fetuses of 1/3 of the 

litters were examined for visceral abnormalities. Fetuses in the remaining 2/3 of the 

litters were examined for skeletal abnormalities. 

No adverse effects were observed on body weight or clinical signs in rats at 125 

mg/kg. At 400 mg/kg, no effect on body weight was observed, but salivation, rales, 

and nasal discharge were observed. At 1,300 mg/kg, one animal died on Gestation 

Day 10 and one animal was sacrificed early on Gestation Day 13. Clinical signs 

observed at 1,300 mg/kg included salivation, rales, nasal discharge, slight inactivity, 

labored breathing, decreased body temperature, soft stools, and staining around the 

mouth, nares, and anogenital area. Mean body weight gains were decreased at 1,300 

mg/kg during the dosing period. The mean body weight gains post-dosing (Gestation 

Days 15-20) were normal compared to control, indicating a reversible effect on body 

weight after test substance withdrawal. 

No adverse effects on pregnancy and no teratogenic effects were observed at any 

level tested. A significant increase in the number of resorptions at 1,300 mg/kg was 

observed compared to control. The number or resorptions was within normal 

expected limits; therefore, the increase was not considered biologically meaningful. 

The maternal NOAEL and LOAEL were 125 and 400 mg/kg, respectively. The 

developmental NOAEL for this study was 1,300 mg/kg. 

Developmental Toxicity - rabbit 

A second developmental toxicity study was conducted with glutaric acid in New 

Zealand White rabbits. Eighteen mated females per dose level were given daily oral 

doses via gavage of the test substance at 0, 50, 160, or 500 mg/kg on Gestation Days 

6-18. Clinical signs, body weights, and food consumption were recorded. On 

Gestation Day 29, the females were sacrificed and examined grossly. Reproductive 

status was determined. Corpora lutea, implantation sites, number of fetuses (live 

and dead), and resorptions (early and late) were recorded. All fetuses were weighed 

and given external, visceral, and skeletal examinations for abnormalities. 

No test substance-related mortality was observed. No changes in body weights or 

clinical signs were observed in females at any level tested. No adverse effects on 

pregnancy, and no embryotoxic or teratogenic effects were observed. Therefore, the 

maternal and developmental NOAEL for this study was > 500 mg/kg. 
11

Developmental Toxicity - rat 

A developmental toxicity study was conducted with adipic acid in Wistar rats. 

Virgin adult females were mated with young adult males, and observation of a 

vaginal sperm plug was considered Day 0 of gestation. Twenty females per dose level 

were given daily oral doses via gavage of the test substance at 0, 2.9, 13, 62, or 288 

mg/kg on Gestation Days 6-15. Clinical signs, body weights, and food consumption 

were recorded. On Gestation Day 20, all animals were subjected to cesarean section, 

and the number of implantation sites, resorption sites, and live and dead fetuses 

were recorded. The urogenital tract of each female was examined in detail for gross 

anatomical normality. The body weights of the liver pups were recorded, and all 

fetuses were examined grossly for the presence of external congenital abnormalities. 

Fetuses of 1/3 of the litters were examined for visceral abnormalities. Fetuses in the 

remaining 2/3 of the litters were examined for skeletal abnormalities. 

The administration of up to 288 mg/kg of adipic acid to pregnant rats for 10 

consecutive days had no effect on nidation, or on maternal or fetal survival. The 

number of abnormalities seen in either soft or skeletal tissues of the test groups was 

similar to the number occurring spontaneously in controls. Therefore, the maternal 

and developmental NOAEL for this study was > 288 mg/kg. 

Developmental Toxicity - rabbit

A second developmental toxicity study was conducted with adipic acid in Dutchbelted rabbits. On Day 0, each doe was given an injection of 0.4 mL of human 

chorionic gonadotropin. Three hours later, each doe was inseminated artificially 

with 0.3 mL of diluted semen from a proven donor buck. On Gestation Days 6-18, 

females were given daily oral doses via gavage of the test substance at 0, 2.5, 12, 54, 

or 250 mg/kg. Clinical signs, body weights, and food consumption were recorded. 

On Gestation Day 29, the females were sacrificed and examined grossly. 

Reproductive status was determined. Corpora lutea, implantation sites, number of 

fetuses (live and dead), and resorptions (early and late) were recorded. All fetuses 

were weighed and given external, visceral, and skeletal examinations for 

abnormalities. 

Treatment of pregnant rabbits with up to 250 mg/kg of adipic acid had no 

significant effect on nidation, or on maternal or fetal survival. The number of 

abnormalities seen in either soft or skeletal tissues of the test groups were similar to 

the number occurring spontaneously in controls. The maternal and developmental 

NOAEL for this study was > 250 mg/kg.]

 4. Subchronic toxicity. [14-day Oral – rat 

DBE was tested in a 14-day oral toxicity study on Crl:CD rats. Groups of 10 male 

rats received feed containing DBE at concentrations of 0 (control), 10,000, 20,000, or 

50,000 ppm for 14 consecutive days. All rats were weighed daily during the test 

period and observations for clinical signs were made at the same time. Food 
12

consumption for the test period was recorded. On the 14th test day, half of the rats 

of each test group were sacrificed. The remaining half of each group were weighed 

every other day, observed for a 14-day recovery period, and sacrificed 14 days later. 

All rats were examined grossly, selected tissues were weighed, and selected tissues 

and organs evaluated histologically. 

Oral administration of DBE to rats over 14 days produced no deaths. No gross or 

microscopic pathologic changes that could be attributed to exposure of DBE were 

detected. No clinical signs other than initial and sporadic weight loss were observed. 

The rate of body weight gain was reduced in rats of the mid- and high-dose group 

with lower food intake by these rats. During the recovery period, test rats in these 

two groups gained slightly more weight than the controls although the high-dose 

rats weighed approximately 7% less at the end of the recovery period. 

 

Except for the observed slight weight gain effects, under the conditions of this test, 

DBE appeared to exhibit a low toxicity in this 14-day feeding study. 

14-day Dermal – rat 

DBE was tested in a 14-day dermal toxicity study on Crl:CD®(SD)IGS BR albino 

rats in accordance with OECD Guideline No. 410 and U.S. EPA (40 CFR Part 792) 

and OECD [C(97)186/Final] Good Laboratory Practice. 

The test substance was applied seven days per week for two weeks to the shaved 

intact dorsal skin of each rat. The application sites were covered with gauze, 

occluded with plastic wrap and secured with non-irritating tape for a period of six 

hours per exposure. Following the exposure period, the application sites were gently 

washed with a solution of non-irritating soap and disposable paper towels to remove 

residual test article. Each test article group consisted of 10 males and 10 females. 

Dosage levels were 100, 300, and 1,000 mg/kg/day. A concurrent control group 

received deionized water on a comparable regimen. The animals were examined 

twice daily for mortality and moribundity. Clinical and dermal observations were 

performed daily, prior to and following exposure, and once each day of the recovery 

period. Detailed physical examinations were performed weekly. Ophthalmological 

examinations were performed prior to dosing and during study weeks 1 and 3. 

Clinical pathology evaluations (hematology, serum chemistry, and urinalysis) were 

performed prior to the scheduled primary necropsy. Complete necropsies were 

performed for all animals and selected organs weighed from animals at the primary 

and recovery necropsies. Select tissues were examined microscopically. 

There were no test article or treatment-related deaths or clinical observations 

following administration of DBE for 14 consecutive days. Minimal to mild dermal 

irritation was observed for all treatment levels near the end of the first week or 

during the second week of dosing. Scabbing of the treated skin was observed at 

necropsy for one male in each of the DBE treatment groups and dark red areas on 

the treated skin was observed for one female in the 1,000 mg/kg/day DBE group; 
13

however, microscopic findings did not indicate a generalized reaction of the treated 

skin to DBE. There were no other test article-related microscopic findings. Body 

weights and food consumption were unaffected by treatment with DBE. There were 

no test article-related changes in hematology, serum chemistry, urinalysis, 

ophthalmoscopy, neurobehavior, or organ weight parameters. Based on these study 

results, the NOEL for systemic toxicity for dermal application of DBE for 14 

consecutive days was considered to be 1,000 mg/kg/day. 

90-day Inhalation – rat 

Groups of 40 male and 40 female Crl:CD®BR rats were exposed six hours/day, five 

days/week to 20, 76, or 390 mg/m3 of DBE vapor. Ten males and 10 females per 

group were exposed to the test substance for seven weeks and 20 males and 20 

females per group (19 males and 19 females in the 76 mg/m3

 group) were exposed to 

the test substance for 13 weeks. After the 13 week exposure phase of the study, 10 

male and 10 female rats from each group underwent a 6-week recovery period. A 

similarly comprised control group was exposed to air only. Exposures were 

conducted in 1.4 m3 stainless steel and glass NYU-style inhalation chambers with air 

flows of approximately 300 liters per minute. 

Rats were weighed weekly throughout the test period and observed daily for clinical 

signs of toxicity. Animals were sacrificed after 7 weeks (10 animals/sex/group) or 13 

weeks of treatment (20 animals/sex/group). The remaining 10 animals/sex/group 

were sacrificed after undergoing a six week recovery period. At sacrifice, samples 

for serum chemistry, hematology, and urinalysis were collected. A gross 

pathological exam was conducted and the heart, kidneys, liver, lungs, spleen, brain, 

thymus, and testis were weighed. The nasal cavities from all rats were examined 

microscopically. 

Degeneration of the olfactory epithelium was observed in male and female rats that 

were exposed to 76 or 390 mg/m3 of DBE for seven weeks. One control female 

showed minimal degeneration of the olfactory epithelium after 7 weeks. After 13 

weeks of exposure, there was degeneration of the olfactory epithelium in female rats 

in all exposure groups although minimal at the lowest dose and in male rats exposed 

to 76 or 390 mg/m3

. Minimal degeneration of the olfactory epithelium was also 

observed in one female from the control group after the recovery period. At the end 

of the 6-week recovery period, nasal effects in DBE-exposed rats included 

disorganization of the olfactory epithelium, decreased numbers of neuronal cells, 

and respiratory metaplasia. These effects are related to tissue repair and 

regenerative processes and were noted at all DBE exposure concentrations in the 

male and female recovery rats. Clinical signs in DBE-exposed rats were similar to 

those of the controls; however, female rats exposed to 390 mg/m3

 of DBE had 

slightly depressed rates of weight gain compared to controls during the exposure 

period. During the recovery period, the weight-gain rate of these rats was similar to 

those of the controls. Liver weights in female rats exposed to 390 mg/m3

 were 

decreased compared to those of the controls. This effect was not present in rats at 
14

the end of the recovery period. A slight decrease in serum sodium concentration was 

observed in male and female rats exposed to 76 or 390 mg/m3 DBE for 13 weeks. 

After the 6-week recovery period, sodium concentrations in the 390 mg/m3 group 

males and females remained slightly low, but the sodium concentrations in the other 

affected groups were no longer different from those of the control group. The NOEL 

in male rats exposed to DBE was 20 mg/m3. A NOEL was not established in females. 

90-day Inhalation – rat

A 90-day inhalation toxicity study on DMS, DMG, and DMA was performed in the 

rat under conditions equivalent to OECD No. Guideline 413 and under U.S. EPA 

(40 CFR Part 792) and OECD [ENV/MC/CHEM(98)17] Good Laboratory Practice. 

Six groups of male and six groups of female Crl:CD®(SD)IGS BR rats each were 

exposed via inhalation to 0, 10, 50, or 400 mg/m3

 DMG, 400 mg/m3 DMS, or 400 

mg/m3

 DMA six hours per day, five days a week over a 90-day period. The exposure 

period was followed by an approximately 1-month recovery period. Rats were 

weighed once per week and clinical signs were taken prior to exposure on days the 

rats were weighed. Group clinical signs were observed during each exposure, and 

the alerting response to an auditory stimulus was checked during each exposure in 

rats visible from the front of the chamber. After each exposure, rats were checked 

for the alerting response to an auditory stimulus prior to removal from chambers 

and were observed for clinical signs immediately as they were returned to their 

cages. Food consumption was determined on a weekly basis. Samples for hepatic, 

lung, and nasal (levels II and III) cell proliferation (CP) were collected from five 

rats/sex/group approximately two weeks after initiation of the study and 

approximately 90 days after study initiation. A clinical pathology evaluation was 

conducted on 10 rats/sex/group designated for subchronic toxicity evaluation 

approximately 45 and 90 days after initiation of the study. Approximately 90 days 

after study initiation, rats designated for the clinical pathology evaluation were 

sacrificed for pathological examination and evaluation of male reproductive 

endpoints, including sperm motility, sperm number, and sperm morphology. A 

neurobehavioral test battery, consisting of functional observational battery 

assessments and motor activity, was conducted on 10 rats/sex/group designated for 

behavioral evaluation and recovery prior to test substance administration to obtain 

baseline measurements, and during test weeks 4, 8, 13, and 18 (recovery). 

Approximately 90 days after study initiation, six rats/sex/group designated for 

neuropathology were sacrificed and evaluated. After approximately one month of 

recovery, rats designated for neuropathological evaluation at this time point were 

sacrificed for evaluation of this endpoint. The estrous cycle of female rats was 

determined for the last 21 days of exposure in rats designated for subchronic 

toxicity evaluation. Following 90 days of exposure, blood was collected via 

the tail vein from 10 rats/sex/group and serum was subjected to hormonal analyses. 

In male rats, serum luteinizing hormone, follicle stimulating hormone, and 

testosterone concentrations were measured. In female rats, serum estradiol and 

progesterone concentrations were measured. 
15

No compound-related effects were observed on mortality, clinical signs, hematology, 

neurobehavioral endpoints, sperm motility or morphology, or estrous cycle 

parameters. 

Male rats exposed to nominal 400 mg/m3 DMG or 400 mg/m3 DMA had lower mean 

body weights and mean body weight gains during the study. In addition, male and 

female rats exposed to 400 mg/m3 DMG had lower food consumption, and male rats 

exposed to 400 mg/m3 DMA had lower food efficiency during the study. Compoundrelated effects were observed in the noses of male and female rats exposed to 400 

mg/m3

 of DMG, DMS, or DMA for 90 days. These effects consisted primarily of 

degeneration/atrophy of the olfactory mucosa of the dorsal meatus and of the 

dorsomedial aspect of the dorsal endoturbinate. Less commonly, focal respiratory 

metaplasia of the olfactory mucosa of the dorsal meatus was also present. Lesions 

were minimal to mild in severity and occurred in higher incidences in the DMG 

group. Degeneration/atrophy of the olfactory mucosa occurred in recovery animals 

in the same locations as was apparent at the 90-day sacrifice in animals exposed to 

DMG, DMS, and DMA. The lesions were usually focal and minimal in severity. The 

incidence of lesions in female recovery groups was higher in the DMG and DMS 

groups compared to the DMA group, while in male recovery groups, incidences 

were somewhat higher for the DMA group. 

Male rats exposed to 400 mg/m3

 DMS and DMA showed significant increased CP in 

the liver at day 14 compared to controls. No significant effects were observed in the 

liver from males evaluated at 90 days or from females evaluated at either time point. 

Female rats exposed to 400 mg/m3

 DMA had significantly greater CP in the lung 

relative to controls at days 14 and 90. No effects on CP were observed in the lung 

from male rats. These liver and lung findings were considered not to bear any 

toxicological relevance. 

Male rats exposed to 400 mg/m3

 DMG and DMA showed significantly greater CP in 

the nose level II compared to controls at day 90. Female rats exposed at 400 mg/m3

DMG had significantly greater CP in the nose level II at day 14. Male rats exposed 

to 400 mg/m3 DMG had significantly greater CP in the nose level III at day 90. CP 

in the nose level III of female rats exposed to 400 mg/m3

 DMG was significantly 

greater than controls on day 14. Female rats exposed at 400 mg/m3 DMS had 

significantly greater CP in the nose level III compared to controls on day 90. 

In male rats exposed to DMG, serum testosterone concentrations were statistically 

significantly decreased at concentrations of 50 and 400 mg/m3

 (59 and 50% of 

control, respectively). Similarly, serum LH concentrations were decreased in a dosedependent manner and were statistically significantly decreased at 400 mg/m3

 (71% 

of control). Serum concentrations of FSH were not affected by DMG treatment. In 

female rats, DMG exposure did not alter serum estradiol or progesterone 

concentrations. In male rats exposed to DMS or DMA, no significant alterations in 

serum hormone concentration were observed. In female rats, DMS caused a 
16

statistically significant decrease in serum estradiol concentrations (43% of control); 

serum progesterone concentrations were not affected. In female rats, DMA exposure 

did not alter serum estradiol or progesterone concentrations. 

There was a treatment-related increase in epididymal sperm counts (per cauda 

epididymis and per gram cauda epididymis) following exposure to DMG and the 

number of sperm per cauda and per gram cauda epididymis was significantly 

increased at 50 and 400 mg/m3 (124-131% of control). Epididymal sperm counts 

were similar to control at 10 mg/m3 DMG. In male rats exposed to DMS, epididymal 

sperm counts (per cauda epididymis and per gram cauda epididymis) were 

significantly increased (153 and 141% of control, respectively). Although not 

statistically significant, a similar trend of increased epididymal sperm counts was 

observed in the DMA group (124 and 114% of control for sperm per cauda and per 

gram cauda epididymis, respectively) that was considered compound-related. 

In conclusion, under the conditions of this study, the NOEC for systemic toxicity 

following repeated exposure to DMG was 10 mg/m3, based on the decreases in 

serum testosterone and serum LH concentrations and increased epididymal sperm 

counts at concentrations of 50 mg/m3 and above. NOECs for DMS and DMA were 

not established, as there were effects in the only concentration (i.e., nominal 400 

mg/m3) of these materials tested. The NOEC for respiratory local toxicity was 50 

mg/m3 DMG, based on olfactory mucosa degeneration and/or atrophy at the highest 

concentration of 400 mg/m3. 

90-day Oral – rat 

A subchronic oral feeding study was conducted with dicarboxylic acids according to 

OECD Guideline No. 408. The dicarboxylic acid mixture tested was composed of 

4% adipic acid, 16% glutaric acid, 5% succinic acid, and up to 4% nitric acid at 

dose levels of 0, 300, 1,000, and 3,000 mg/kg. Fifteen male and fifteen female 

Sprague Dawley rats were assigned to each dose level and were administered vehicle 

(deionized water) or test substance daily by oral gavage for 90 days. Animals were 

observed daily, body weight and food consumption were recorded weekly. After 13 

weeks of treatment, hematology, chemistry, and urinalysis parameters were 

analyzed for 10 rats/sex/group. Ophthalmoscopic exams were also conducted on all 

animals at 13 weeks. At termination, all animals were sacrificed and necropsied. 

Select organ weights and tissues were collected. Microscopic examination was 

performed for tissues collected on all high dose and control animals. 

At the high dose level (3,000 mg/kg), treatment related deaths were observed in 2/5 

males and 1/15 females. Animals at this dose level also had an increased incidence of 

labored breathing and rales. Reduced body weight was noted in males and females, 

and statistically significant reductions in food consumption were noted in males only 

at 3,000 mg/kg. Body weight gain was slightly reduced only in females (not 

statistically significant) and statistically significant reduced food consumption was 

noted only in males at 1,000 mg/kg. Statistically significant increased leukocytes 
17

were noted in males and reduced urine pH in males and females at 3,000 mg/kg and 

reduced urine pH in males only at 1,000 mg/kg. No effects were noted in animals at 

300 mg/kg. Organ weights and tissues examined microscopically were normal in all 

groups. In conclusion, the No Observed Adverse Effect Level (NOAEL) for 

administration of dicarboxylic acids daily for 13 weeks to rats was 300 mg/kg and 

the Lowest Observed Adverse Effect Level (LOAEL) was 1,000 mg/kg). 

90-day Oral – rat 

A subchronic oral feeding study similar to OECD Guideline No. 408 was conducted 

with glutaric acid. Fifteen male and fifteen Sprague-Dawley rats per dose group 

were exposed to 0, 0.5, 1.0, or 2.0% glutaric acid in feed for 90 days. Mortality, 

clinical observations, and body weights were recorded. Food consumption was 

calculated for five males and five females per group. Hematology, blood chemistry, 

and urinalysis parameters were evaluated for five males and five females from the 

high dose group (2%) and control group (0%) at Days 45 and 84. At sacrifice, 

animals were examined grossly and organ weights were collected. Hematoxylin and 

eosin fixed tissues were examined microscopically from 10 males and 10 females 

from the high dose group (2%) and control (0%) group. 

No treatment-related mortality was noted and food consumption was normal. 

Statistically significant reduced body weight gain was observed in females at the 2% 

dose level. Males at 2% also had reduced body weight gain although not statistically 

significant. No statistically significant differences were noted in hematology, blood 

chemistry, and urinalysis results. There were no histopathological findings or organ 

weight changes attributed to the test substance. Therefore, the NOAEL for glutaric 

acid was ≥1% and the LOAEL was 2%. 

90-day Oral – rat 

A thirteen week repeated dose study was conducted with monosodium succinate in 

Fischer F344 rats. The test substance was dissolved in distilled water, and ten male 

and ten female rats per dose level were administered the test substance at 0.3, 0.6, 

1.25, 2.5, 5, or 10% ad libitum in their drinking water for 13 weeks. Rats were 

observed daily for mortality and clinical signs. Body weight was measured every 

other week. After 13 weeks of treatment, all surviving rats were euthanized and 

necropsied. Animals were examined grossly and tissues were collected for 

microscopic examination. Samples for hematology and clinical chemistry were also 

collected at termination. 

All of the rats in the 10% group died during the first four weeks of the study, 

following a severe suppression of body weight gain. No fatalities were observed in 

the other dose groups until termination. Suppression of body weight gain was 

observed at ≥ 2.5%. The volume of drinking water consumed was very small in the 

highest dose groups, although it was larger in the 5% group than in the other 

groups. No dose-related effects were observed in the clinical pathology evaluation. 
18

Rats that died during the study were severely emaciated. However, test articlerelated lesions were not noted in any of the tissues examined microscopically, 

although atrophy was observed. On the basis of body weight depression, the 

maximum tolerated dose of monosodium succinate was determined to be 

approximately 2-2.5% when administered in the drinking water. 

90-day Oral – dog 

A subchronic oral feeding study was conducted with glutaric acid in beagle dogs. 

Four male and four female dogs per dose level were administered the test substance 

daily in feed for 90 days at dose levels of 0, 1, 3, and 5% (Days 1-10) then at 0, 0.5, 1, 

and 2% (Days 11-90). Dogs were observed for mortality, clinical signs, body weights 

and food consumption. Samples for hematology, blood chemistry, and urinalysis 

were collected at Days 45 and 85. At terminal sacrifice, organ weights were recorded 

and tissues were collected for microscopic examination. 

Body weight loss was observed in males and females at the 5% and 3% dose levels, 

respectively, after 10 days. Reduced food consumption was also observed in parallel. 

Overall, the low- and mid- dose animals had weight gains comparable to controls. 

Five of the eight high dose dogs did not gain weight. No other treatment-related 

effects were noted. Therefore, the NOAEL was ≥ 2% and the LOAEL was 3%.]

 5. Chronic toxicity. [Carcinogenicity

No experimental carcinogenicity study is available on DME. The two principal 

chemical structures present in DME, that is, DMG and DMS, were assessed using 

the knowledge-based expert system DEREK for Windows (software version DfW 

9.0.0,14_08_2006). The expert system DEREK has been designed for the qualitative 

prediction of the possible toxicity of chemicals and the following endpoints were 

searched for this structure: carcinogenicity, genotoxicity, HERG channel inhibition, 

irritation, respiratory sensitization, skin sensitization, thyroid toxicity, and 

miscellaneous endpoints. The toxicity assessments are based on the presence of 

specific substructures. 

The structures, DMG and DMS, did not trigger any alerts with any degree of 

likelihood in the expert system DEREK. Further, the dimethyl esters are expected to 

undergo enzymatic hydrolysis upon ingestion by ubiquitous carboxylesterases 

(Satoh et al., 2002 and Hosokawa, 2008) to form the corresponding dicarboxylic 

acids and methanol. No specific findings were detected in the repeated dose toxicity 

studies available by the oral route on the dicarboxylic acids, or in the 

chronic/carcinogenicity studies conducted with the monosodium succinate and 

adipic acid. 

Finally, considering the absence of findings in the genotoxicity assays available in 

vitro and in vivo on DME or on the individual diesters, there is a low concern for a 

carcinogenicity potential that would be relevant to the foreseen uses. 
19

Chronic Oral Toxicity/Carcinogenicity – rat

A two-year carcinogenicity study was conducted with monosodium succinate in 

Fischer F344 rats. Fifty males and fifty females per dose group were administered 

the test substance ad libitum in their drinking water at dose levels of 0, 1, or 2%. The 

solutions were replaced with freshly prepared solution three times per week and the 

amount of solution consumed was measured to calculate the intake of the test 

substance. After 104 weeks of treatment, the rats underwent a recovery period in 

which they were administered distilled water for 9 weeks. Animals were observed 

daily for clinical signs and mortality. Body weight was recorded weekly for the first 

13 weeks and then once every four weeks thereafter. Rats that died or were 

euthanized during the study underwent a necropsy that included macroscopic 

examination and collection of tissues for microscopic examination. At week 113, all 

surviving rats were euthanized and necropsied. A macroscopic examination was 

conducted and tissues were collected for microscopic examination. 

The intake of monosodium succinate was 0, 196, and 437 mg/rat/day at 0, 1, and 

2%, respectively, for males and 0, 146, and 309 mg/rat/day at 0, 1, and 2%, 

respectively, for females. 

In males, the mortality rate in the control group was slightly higher than that in 

the other two groups throughout the experiment. A dose-dependent decrease in 

growth rate was apparent in both sexes. In males, the overall tumor incidence was 

almost 100% in all groups, including the control group. In females, it was 

approximately 77-82% in all three groups. In both sexes, there were no 

statistically significant differences between the control and treated groups in 

overall tumor incidences and mean survival times. 

Tumors were found in many organs or tissues in all groups including the controls. 

In males of all groups, tumors of the testes were the most frequent, followed by 

those of the hematopoietic organs, thyroid, adrenals, mammary, prostate, pancreas, 

and pituitary. Tumors of the uterus, pituitary, hematopoietic organs, mammary 

gland, thyroid, and adrenals were the most common in females. Tumors were also 

detected in other organs or tissues, but the incidences were very low. None of the 

treated groups showed a significant increase in the incidence of any tumors over 

that in the corresponding controls, while the incidence of endometrial stromal polyp 

in the females given the 2% dose was significantly lower than that in the control 

group. The incidence of C-cell adenoma/carcinoma of the thyroid in the females 

given 2% was higher than that in the controls, although marginally not significant, 

and a positive trend was noted in the occurrence of this tumor by an age-adjusted 

statistical test. Histologically, all tumors, except prostate tumors, observed in this 

study were similar to those that are known to occur spontaneously in this strain of 

rats. Prostate tumors were observed in all male groups, including the control group, 

at incidences much higher than those reported by others. Histologically, the prostate 

tumors were all intraductal adenomas/carcinomas. In addition to these tumors, 

many kinds of non-neoplastic lesions, such as myocardial fibrosis, bile duct 
20

proliferation, and chronic nephropathy were observed in all groups including 

controls, and no other specific lesions were detected in any treated groups of either 

sex. Therefore, it was concluded that monosodium succinate had no carcinogenic 

activity in F344 rats when administered continuously in the drinking water for 2 

years . 

Chronic Oral Toxicity/Carcinogenicity – rat

A two year chronic feeding study was conducted with adipic acid in rats. Twenty 

male and nineteen females per dose group were fed either the basal laboratory diet 

or basal diet with adipic acid added at concentrations of 0, 0.1, 1.0, 3.0, or 5.0% 

(males) and 0 or 1.0% (females) ad libitum for two years. Body weight, food 

consumption, and general appearance were recorded weekly. Whenever possible, 

animals that died were examined, and gross pathology was performed. After two 

years, surviving rats were euthanized, select organs were weighed, and tissues were 

taken for microscopic examination. Rats were also examined for the incidence of 

tumors. 

The average test substance consumed per rat per day was 1.69, 174.88, 506.07, and 

813.62 mg for the 0.1, 1.0, 3.0, and 5.0% dose groups, respectively. There were no 

significant differences in body weight gains in females and in males treated with 0.1 

or 1.0% adipic acid. During the rapid growth period, the weight gains of males in 

the 3.0 and 5.0% dose groups were significantly less than the control groups. 

Throughout the latter half of the study, the average body weights were not 

remarkable, although the 5.0% dose group was consistently the lowest. There were 

no significant differences in food consumption for females. There was a slight, but 

consistent, reduction in food consumption in males of the 5.0% dose group. The 

following clinical signs were observed among males in all groups, including 

controls: wheezing, blood-tinged crust about the noses and eyes, and body sores. 

The incidence of these findings did not appear to be significantly different among 

the groups although a lower incidence of signs indicative of respiratory infection 

and body sores occurred in the 5.0% adipic acid group. Clinical signs noted in 

females of the control and test article groups included blood-tinged crust about the 

eyes and noses, unthriftiness, and body sores. The incidence of lung pathology and 

tumor growth appeared to be equally distributed among all groups, including the 

controls. There were no significant differences in organ weights or gross or 

microscopic pathology. Soft edematous testes were noted at least as frequently in 

males of the control group as in those in the adipic acid treatment groups. Two of 

the surviving female control rats and one experimental animal had ovarian tumors; 

ovarian cysts were noted in both control and experimental rats. Therefore, it can be 

concluded that a NOAEL for males and females is 1%.]

 6. Animal metabolism. [NA-Remove.] 
21

 7. Metabolite toxicology. [Dimethyl esters are hydrolyzed by carboxylesterases 

to form naturally occurring dicarboxylic acids (glutaric acid, succinic acid, and 

adipic acid). Mammalian carboxylesterases are expressed in a number of tissues in 

human adults and in rats; therefore, the dimethyl esters are likely to be hydrolyzed 

to the respective dicarboxylic acids in tissues such as the gastrointestinal tract and 

liver. For that reason, the toxicological properties of these metabolites were also 

considered and presented in the tolerance exemption petition to support the 

toxicological profile of DME.]

 8. Endocrine disruption. [There is no available evidence demonstrating that 

DME is an endocrine disruptor in humans.]

C. Aggregate Exposure

 1. Dietary exposure. [In examining aggregate exposure, section 408 of the 

Federal Food, Drug, and Cosmetic Act (FFDCA) directs EPA to consider available 

information concerning exposures from the pesticide residue in food and all other 

nonoccupational exposures, including drinking water from ground water or surface 

water and exposure through pesticide use in gardens, lawns, or buildings 

(residential and other indoor uses). 

It is anticipated that DME will be used as a solvent/co-solvent in EC formulations at 

a concentration no higher than 40%. DME is not expected to be persistent in the 

environment based on a PBT assessment of its components, DMG, DMS, and DMA 

and of its primary metabolites, glutaric acid, succinic acid, and adipic acid. Further, 

DME has a low toxicity profile as demonstrated through acute, subchronic, 

reproductive, developmental, and mutagenicity testing. Therefore, dietary exposure 

to DME should not be of concern. 

DME will not be applied directly to water. Agricultural practices minimize spray 

drift and typical end-use product labels prohibit direct application to water. DME is 

readily biodegradable and is not expected to be persistent in the environment. 

Therefore, use of DME as a solvent/co-solvent in EC formulations does not pose a 

risk to drinking water. 

The intended use of DME is as a solvent/co-solvent in agricultural pesticide 

formulations applied to food/feed crops. Therefore, exposure to nonoccupational use 

of DME in gardens, lawns, or buildings (residential and other indoor uses) is not 

expected to occur. 

Overall, DME is considered to be a low toxicity substance with a reasonable 

certainty of no harm from dietary exposure and all other nonoccupational sources 

of exposure.]

 i. Food. [NA-Remove.]

 ii. Drinking water. [NA-Remove.]
22

 2. Non-dietary exposure. [NA-Remove.]

D. Cumulative Effects

 [Section 408(b)(2)(D)(v) 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 the particular pesticide’s residues 

and other substances that have a common mechanism of toxicity. 

Rhodia has not found DME to share a common mechanism of toxicity with any 

other substances, and DME does not appear to produce a toxic metabolite produced 

by other substances. 

Resultant risks, separately and/or combined with other substances that may have a 

common mechanism of toxicity, should be low for DME. Rhodia does not expect any 

adverse cumulative effects associated with the use of DME.] 

E. Safety Determination

 1. U.S. population. [DME exhibits a low toxicity profile, as demonstrated by 

the acute, subchronic, chronic/carcinogenicity, reproductive, and developmental 

studies summarized above. In a chromosome aberration test, DBE was positive at 

high concentrations in the presence of S9 metabolic activation; however, all other in 

vitro and in vivo genotoxicity studies conducted with DBE and DMG were negative. 

It is possible that in the presence of S9 metabolic activation, the esters were 

hydrolyzed and the dicarboxylic acids released, making the pH more acidic. This is 

known to cause false positive effects in cytogenicity assays. 

When DME is used on raw agricultural commodities in accordance with good 

agricultural practice, it is expected to meet EPA’s reasonable certainty of no harm 

requirement. Based on the low toxicity profile of DME, there is no reason to believe 

that adverse effects on the U.S. population will result from the use of this inert 

ingredient in pesticide formulations. 

 2. Infants and children. [DME exhibits a low toxicity profile, as demonstrated by 

the acute, subchronic, chronic/carcinogenicity, reproductive, and developmental 

studies summarized above. While some hormonal variations were observed in the 

90-day inhalation toxicity study with DMG, there were no compound-related effects 

on sperm motility or morphology, or estrous cycle parameters in that study, and no 

specific alerts were identified in the reproductive (one-generation) and 

developmental toxicity studies with DBE by the inhalation route or with 

dicarboxylic acids by the oral route. There was no specific neurotoxicity study 

available, but no neurobehavioral effects were observed in the 90-day repeat dose 

toxicity study conducted with DMG, DMS, and DMA. 
23

When DME is used on raw agricultural commodities in accordance with good 

agricultural practice, it is expected to meet EPA’s reasonable certainty of no harm 

requirement. There is no reason to believe that infants and children will be 

disproportionately at risk to the use of DME in pesticide formulations.] 

F. International Tolerances

 [There are no known international tolerances or tolerance exemptions for 

DME.]