Registration Dossier

Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Not applicable
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-study according to OECD guideline 407.
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1986

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Ethyl-3-ethoxypropionate; EEE Solvent
- Analytical purity: The purity of the test substance as determined by gas chromatography with flame ionization detection (GC/FID) was 99.9%.
- Lot/batch No.: X-18626-184-7

Test animals

Species:
rat
Strain:
other: CRL: CD® (SD)BR
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington, MA
- Age at study initiation: 6 weeks old (males) and 8 weeks old (females)
- Weight at study initiation: approximately 212±5 g (males) and 183±7 g (females)
- Fasting period before study: no
- Housing: Rats were housed in groups of five segregated by sex.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: approximately two weeks prior to testing


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-24
- Humidity (%): 50-54
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): A photoperiod of 12 hours from 6 a.m. to 6 p.m. was maintained.


Administration / exposure

Route of administration:
oral: gavage
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
Oral gavage (no vehicle)
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
No data
Duration of treatment / exposure:
29 days
Frequency of treatment:
20 doses. Doses were given 5 days per week excluding holidays.
Doses / concentrations
Remarks:
Doses / Concentrations:
100 or 1000 mg/kg/day
Basis:
actual ingested
No. of animals per sex per dose:
Five
Control animals:
yes
Details on study design:
Five male and five female rats (CRL: CD*(SD)BR) from Charles River Breeding Laboratories, Wi.lmington, MA, were randomly assigned to each test group. Animals were isolated for approximately two weeks prior to testing. At the start of the study, rats were approximately 6 (males) and 8 (females) weeks old and weighed approximately ca. 212 g (males) and ca. 183 g (females). Rats were chosen for this study because they are a common representative species for toxicity studies.
Positive control:
none

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Every workday afternoon

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Every workday morning

BODY WEIGHT: Yes
- Time schedule for examinations: Days 0, 4, 7, 11, 15, 21, and 28.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Time schedule for examinations: Days Days 4, 7, 11, 15, 18, 21, 25, and 28.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

FOOD EFFICIENCY:
- No data

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At the time of necropsy
- Anaesthetic used for blood collection: Yes; CO2
- Animals fasted: Yes
- How many animals: Five per sex
- Parameters examined: hemoglobin concentration, hematocrit, red blood cell count, white blood cell count, differential white blood cell count, platelet count, red blood cell indices, and examination of the blood smears for cellular morphology.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At the time of necropsy
- Animals fasted: Yes
- How many animals: Five per sex
- Parameters examined: aspartate aminotransferase, alanine aminotransferase, sorbitol dehydrogenase, alkaline phosphatase, creatinine, urea nitrogen, and glucose.

URINALYSIS: No data

NEUROBEHAVIOURAL EXAMINATION: No data



Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes. The following organs were fixed in 10% buffered formalin: trachea, lungs, heart, tongue, esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, pancreas, liver, salivary glands, kidneys, urinary bladder, pituitary gland, adrenal glands, thyroid glands, parathyroid glands, thymus, spleen, mesenteric lymph nodes, bone marrow (femoral), brain, testes, epididymides, male accessory sex glands, ovaries, vagina, uterus, Fallopian tubes, and gross lesions. Eyes were fixed in a modified Zenker's solution. All tissues were examined microscopically from the control and high-dose groups and target organs and gross lesions were examined from other groups.
Other examinations:
Organ weights
- liver and kidneys were weighed.
Statistics:
Mean values were calculated for body weight, feed consumption, organ weights, hematology, and clinical chemistries. All mean data, except feed consumption, were evaluated using the following computer-generated statistical tests: one-way analysis of variance (ANOVA), Bartlett's test, and Duncan's multiple range test using a P value of < 0.05 to indicate statistical significance. Feed consumption was not analyzed statistically because the animals were group housed.

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS
No compound-related adverse effects were observed.

MORTALITY
Two high-dose animals died post-dose on Day 3 of the study. The cause of death was due to intratracheal injection of the test compound. These
animals were replaced on Day 3 of the study.

BODY WEIGHT AND WEIGHT GAIN
The two animals that were used as replacements were of a comparable weight to both the animals in the control and the high-dose groups when placed on the study. A significant decrease in body weight gain observed on Day 4 of the study was solely due to an initial weight loss in these two animals. The lost weight was subsequently regained. The body weight was otherwise comparable to the controls for all test animals.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
The feed consurnption was otherwise comparable to the controls for all test animals.

HAEMATOLOGY
The hematologic determinations were comparable to the controls at both dose levels in both sexes

CLINICAL CHEMISTRY
At 1000 mg/kg the aspartate aminotransferase and creatinine levels were slightly increased in both sexes, though the later was statistically significant in only the females. The sorbitol dehydrogenase levels were moderately increased in the males and slightly increased in the females, and the alanine aminotransferase levels were slightly increased in the females. The clinical chemistry determinations of the 100 mg/kg males were comparable to the controls.

ORGAN WEIGHTS
The relative and absolute liver and kidney weights of both dose levels in both sexes were comparable to the controls.

GROSS PATHOLOGY/ HISTOPATHOLOGY: NON-NEOPLASTIC
No compound-related changes were observed. The lungs from the two animals that died showed lesions due to intrapulmonary injection of the test compound.

Effect levels

open allclose all
Dose descriptor:
NOEL
Effect level:
100 mg/kg bw (total dose)
Sex:
male/female
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Slight increase in aspartate aminotransferase, creatinine, alanine aminotransferase and sorbitol dehydrogenase levels.

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

Not applicable

Applicant's summary and conclusion

Conclusions:
The no observed adverse effect level (NOAEL) for Ethyl 3-Ethoxypropionate is 1000 mg/kg bw/day based on slight changes in liver enzymes. The no observed effect level is 100 mg/kg bw/day.
Executive summary:

The test compound did not produce adverse clinical signs, changes in the feed consumption, hematological determinations, and organ weights, or morphological changes in organs and tissues. Mortality was observed on Day 3 in two animals that received the test material intratracheal. The test compound produces no mortality when administered into the gastrointestinal tract. The two animals that replaced the animals that died, though of a comparable weight when placed on the study, lost weight overnight. Their loss of weight caused the mean body weight of the high-dose group to be significantly lowered on Day 4. The lost weight was subsequently regained. With the exception of this incident, the body weights of all test animals were comparable to the controls throughout the study. At 1000 mglkg, the aspartate aminotransferase and creatinine levels were slightly increased in both sexes, the sorbitol dehydrogenase levels were moderately increased in the males and slightly increased in the females, and the alanine aminotransferase levels were slightly increased in the females. The clinical chemistry determinations of the 100 mg/kg males were comparable to the controls. The probable site of toxic action is the liver. The no observed adverse effect level (NOAEL) for Ethyl 3-Ethoxypropionate is 1000 mg/kg bw/day based on slight changes in liver enzymes. The no observed effect level is 100 mg/kg bw/day.