Registration Dossier

Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: official guideline method, GLP with certificate, good and extensive documentation, identity of substance clear but no details on its purity

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))
Qualifier:
according to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test material as stated in study report ("Sponsor's identification"): MEC
Description: clear colourless liquid
Lot number: 009141
Date received: 11.27.2000
Storage conditions: stored at room temperature in the dark until 01.16.2001, thereafter stored at 4 °C in the dark

Remark of the author of this IUCLID dossier concerning the substance identity:
Every page of the copy of the study report contains an annotation referring to the data sharing agreement in place between the licensee that uses this study report and the data owner. In this data sharing agreement the identity of the chemical substance is specified with "Ethyl Methyl Carbonate - EC No. 433-480-9, CAS Nr. 623-53-0".

Test animals

Species:
rat
Strain:
other: Sprague-Dawley Crl:CD (registered trademark) IGS BR
Sex:
male/female
Details on test animals and environmental conditions:
Forty (Twenty males and twenty females) Sprague-Dawley Crl:CD(R) (SD) IGS BR strain rats of good health were used in the study.
Animal delivery from Charles River (UK) Limited, Margate, Kent.
Animal weight before study: males 125-163 g, females 126-150 g
Animal age: approximately five to six weeks
Acclimatisation period: 8 d
Animal identification: uniquely identified by ear punching system

Husbandry: groups of 5, separation by sex, polypropylene grid-floor cages suspended over trays lined with absorbent paper, drinking water (in polycarbonate bottles attached to cage) and food ad libitum (pelleted diet: Rat Mouse SQC Expanded Diet No. 1, Special Diets Services Limited, Witham, Essex, UK), wooden chew blocks in cages (B & K Universal Ltd., Hull, UK). Drinking water and diet were considered to be free of any contaminants that would have affected the study results. Temperature: 21 +/- 2 °C, relative humidity 55 +/- 15 %, light-darkness cycle 12 h/12 h (low intensity fluorescent lighting), at least 15 air changes/h.

The animals were randomly allocated to treatment groups using random letter tables and the group mean body weights were then determined to ensure similarity between treatment groups. The cage distribution within the holding rack was also randomised.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: Arachis oil BP
Details on oral exposure:
The test material was administered daily, for twenty-eight consecutive days, by gavage using a stainless steel cannula attached to a disposable plastic syringe. Control animals were treated in an identical manner with 2 mL/kg/day of Arachis oil BP.
Analytical verification of doses or concentrations:
yes
Duration of treatment / exposure:
by gavage to three groups, each of five male and five female Sprague-Dawley Crl:CD(R) (SD) IGS BR strain rats, for twenty-eight consecutive days
Frequency of treatment:
The test material was administered daily.
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 15, 150, 1000 mg/kg/day
Basis:
other: concentrations of test substance in Arachis oil BP
No. of animals per sex per dose:
5
Control animals:
yes, concurrent vehicle

Examinations

Observations and examinations performed and frequency:
Clinical observations: All animals were examined for overt signs of toxicity, ill-health or behavioural change immediately before dosing and one and five hours after dosing during the working week. Animals were observed immediately before dosing and one hour after dosing at weekends. All observations were recorded.

Functional/behavioural toxicity observations: gait, tremors, twitches, convulsions, bizarre/abnormal/stereotypic behaviour, salivation, pilo-erection, exophtalmia, lachrymation, hyper/hypothermia, skin colour, respiration, palebral closure, urination, defecation, transfer arousal, tail elevation; motor activity assessment, forelimb/hindlimb grip strength, sensory reactivity: grasp response, vocalisation, toe pinch, tail pinch, finger approach, touch escape, pupil reflex, startle reflex, blink reflex.

Monitoring of food and water intake and body weights throughout the study.

Haematological and blood chemical investigations: haemoglobin, erythrocyte count, haematocrit, erythrocyte indices, total leukocyte count, differential leukocyte count, platelet count, reticulocyte count (cresyl blue stained slides prepared but reticulocytes not assessed), prothrombin time (by Hepato Quick), Activated partial thromboplastin time (by Preci Clot); urea, glucose, total protein, albumin, albumin/globulin ratio, sodium, potassium, chloride, calcium, inorganic phosporus, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine, total cholesterol, total bilirubin

Pathology: after dosing experiment animals killed by intravenous overdose sodium pentobarbitone; followed by exsanguination.
full external and internal examination; recording of macroscopic abnormalities: adrenals, brain, epididymides, heart, kidneys, liver, ovaries, spleen, testes, thymus; histopathology (exminations by Precision Histology International, Norfolk, UK): adrenals, aorta (thoracic), bone & bone marrow (femur incl. stifle joint, sternum), brain (incl. cerebrum, cerebrellum and pons), caecum, colon, duodenum, epididymides, eyes, gross lesions, heart, ileum, jejunum, oesophagus, ovaries, testes, pancreas, pituitary, prostate, rectum, salivary glands (submaxillary), sciative nerve, seminal vesicles, skin (hind limb), spinal cord (cervical), spleen, stomach, kidneys, liver, lungs (with bronchi), lymph nodes (cervical and mesenteric), muscle (skeletal), thymus, thyroid/parathyroid, trachea, urinary bladder, uterus

Extensive statistical evaluation of data including: group mean values, standard deviations, ANOVA, Levene's test, Dunnett's test, Kruskal-Wallis ANOVA, Mann-Whitney 'U' test. p >= 0.05 considered as not significant

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Description (incidence and severity):
for male rats confined to 1000 mg/kg/day, for eather sex treated with 150 or 15 mg/kg/day
Mortality:
no mortality observed
Description (incidence):
for male rats confined to 1000 mg/kg/day, for eather sex treated with 150 or 15 mg/kg/day
Body weight and weight changes:
no effects observed
Description (incidence and severity):
no adverse effect on bw development was detected
Food consumption and compound intake (if feeding study):
no effects observed
Water consumption and compound intake (if drinking water study):
no effects observed
Haematological findings:
no effects observed
Description (incidence and severity):
no treatment-related effects were detected
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
no toxicologically significant effects were detected

Effect levels

open allclose all
Dose descriptor:
NOEL
Effect level:
1 000 mg/kg bw/day (nominal)
Sex:
male
Dose descriptor:
NOEL
Effect level:
150 mg/kg bw/day (nominal)
Sex:
female

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

Summary of results:

Oral administration of the test material, MEC to rats for a period of twenty-eight consecutive days at dose levels of up to 1000 mg/kg/day produced minor treatment-related changes confined to 1000 mg/kg/day females. No such effects were demonstrated in males treated with 1000 mg/kg/day or animals of either sex treated with 150 mg/kg/day or 15 mg/kg/day.

Mortalities: none

Clinical observations: Clinical signs were confined to 1000 mg/kg/d females who showed an isolated instance of increased salivation detected up to ten minutes after dosing on Day 5 and hunched posture from Day 14 onwards. It was further concluded in the study report that in view of the isolated nature and absence of supporting evidence to the contrary these findings was considered to be of dubious toxicological significance. No treatment-related clinical signs were detected in 1000 mg/kg/day males or animals of either sex treated with 150 or 15 mg/kg/d.

Behavioural Assessements: Detailed open-field observations confirmed the clinical signs of hunched posture detected in 1000 mg/kg/d females from Week 2 onwards. No effects were detected in 1000 mg/kg/d males or in animals of either sex treated with 150 or 15 mg/kg/d. All remaining inter and intra group differences in behavioural scores were considered to be a result of normal variation for rats of the strain and age used and were of no toxicological importance.

Functional Performance Tests: There were no treatment-related changes in the functional performance parameters measured. Statistical analysis of the data revealed no significant intergroup differences

Sensory Reactivity Assessments: There were no treatment-related changes in sensory reactivity. All inter and intra group differences in sensory reactivity scores were considered a result of normal variation for rats of the strain and age used and were of no toxicological importance. Statistical analysis of the quantitative data revealed no significant intergroup differences.

Blood Chemistry: There were no treatment-related changes detected in the blood chemical parameters measured. Statistical analysis of the data revealed no significant intergroup differences.

Pathology:

Necropsy: No treatment-related macroscopic abnormalities were detected.

Histopathology: There were no treatment-related microscopic changes observed.

Applicant's summary and conclusion

Conclusions:
No effects were demonstrated in male rats treated with 1000 mg/kg/day or animals of either sex treated with 150 mg/kg/day or 15 mg/kg/day. The "No Observed Effect Level" was considered to be 1000 mg/kg/day in males and 150 mg/kg/day in females.

The substance does not need to be classified according to REGULATION (EC) No 1272/2008 (of 16 Dec 2008), 3.9. Specific target organ toxicity — repeated exposure. The highest concentration range for oral exposure (in a 90-d study) that justifies classification when significant toxic effects are observed is 10 < C ≤ 100 mg/kg bw/d. The lowest NOEL is above this range in this study (150 mg/kg bw/d) and furthermore for classification 90-d-study data would be required.