3-methyl-1-vinyl-1H-imidazolium chloride

Endpoint summary

Description of key information

No adverse effects were observed up to the limit dose tested (1000 mg/kg bw/d). Thereby, the following NOAEL (no observed adverse effect level) of the test article analogue 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate were determined:
a) NOAEL for general, systemic toxicity was 1000 mg/kg bw/d for the F0 females and males
b) NOAEL for reproductive performance and fertility was 1000 mg/kg bw/d for the F0 parental rats

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2012-02-09 and 2013-05-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-conform study in accordance to OECD guideline and US EPA guideline; for read-across justification, please refer to section 13.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS 870.3650 (Combined Repeated Dose Toxicity Study With the Reproduction/Developmental Toxicity Screening Test) 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH
- Age at study initiation: 11-12 weeks
- Weight at study initiation: Male animals: 339.0 g - 372.4 g, Female animals: 191.1 g - 225.1 g
- Housing: individually in Makrolon type M III cages
- Diet: ad libitum, Kliba maintenance diet mouse/rat “GLP” meal (Provimi Kliba SA, Kaiseraugst, Switzerland)
- Water: ad libitum
- Acclimation period: 8 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: For the preparation of the administration solutions the test substance was weighed in a calibrated beaker depending on the dose group, topped up with drinking water and subsequently intensely mixed with a magnetic stirrer until it was completely dissolved. The analytical results indicated that the test substance is stable in drinking water over a period of 7 days.

DIET PREPARATION
- Rate of preparation of diet (frequency): at the beginning of the administration period and thereafter in intervals

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The sample preparation were analytically verified by using HPLC method coupled with a DAD. Therefore, approx. 0.05 g of the test substance was dissolved to 100 mL usind drinking water. All determined concentrations were in the range between 90% and 110% of the nominal concentration, demonstrationg the correctness of the preparations.

Duration of treatment / exposure:

females: 49 days
males: 34 days

Frequency of treatment:

once daily

Remarks:

Doses / Concentrations:
100, 300, 1000 mg/kg bw/d
Basis:
nominal in water

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Positive control:

no data

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least once daily
- Cage side observations checked: any signs of morbidity, pertinent behavioral changes and signs of overt toxicity

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once prior to the first administration and at weekly intervals during the administration period

BODY WEIGHT: Yes
- Time schedule for examinations: once a week

FOOD CONSUMPTION: Yes
- once a week

WATER CONSUMPTION: not examined

OPHTHALMOSCOPIC EXAMINATION: not examined

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the treatment period
- Anaesthetic used for blood collection: Yes (Isoflurane)
- Animals fasted: Yes
- How many animals: 5
- Parameters checked: Leukocyte count (WBC), Erythrocyte count (RBC), Hemoglobin (HGB), Hematocrit (HCT), Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), Mean corpuscular hemoglobin concentration (MCHC), Platelet count (PLT), Differential blood count, Reticulocytes. Furthermore clotting tests were performed (parameter checked: Prothrombin time (Hepato Quick’s test) (HQT)).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the end of the treatment period
- Anaesthetic used for blood collection: Yes (Isoflurane)
- Animals fasted: Yes
- How many animals: 5
- Parameters checked: Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP), γ-Glutamyltransferase (GGT), Sodium, Potassium, Chloride, Inorganic phosphate, Calcium, Urea, Creatinine, Glucose, Total bilirubin, Total protein, Albumin, Globulins, Triglycerides, Cholesterol, Bile acids

URINALYSIS: Yes
- Time schedule for collection of urine: overnight (at the end of the treatment period)
- Metabolism cages used for collection of urine: Yes (withdrawal of food and water)
- Animals fasted: Yes
- Parameters checked: pH, protein, glucose, ketones, urobilinogen, bilirubin, blood, specific gravity, sediment, color, turbidity, volume

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: at the end of the adminstration period
- Dose groups that were examined: 5 males and 5 femles (with litter) per group
- Battery of functions tested: sensory activity, home cage observations, open field observations, motor activity

Sacrifice and pathology:

- MORTALITY
- GROSS PATHOLOGY: Yes (adrenal glands, aorta, bone marrow (femur), brain, cecum, cervix, coagulating gland, colon, duodenum, eyes with optic nerve, esophagus, extraorbital lacrimal glands, epididymides, femur with knee joint, heart, ileum, jejunum, kidneys, larynx, liver, lungs, lymph nodes, mammary gland, nose, ovaries, oviducts, pancreas, parathyroid glands, pharynx, pituitary gland, prostate gland, rectum, salivary glands, sciatic nerve, seminal vesicles, skeletal muscle, spinal cord, spleen, sternum with marrow, stomach, testes, thymus, thyroid, glands, trachea, urinary bladder, uterus, vagina)
- HISTOPATHOLOGY: Yes (adrenal glands, all gross lesions, bone marrow (femur), brain, cecum, cervix, coagulating glands, colon, duodenum, epididymes, heart, ileum, jejunum, kidneys, liver, lungs, lymph nodes, ovaries, oviducts, prostate gland, peyer's patches, rectum, sciatic nerve, seminal vesicles)

Other examinations:

- Organ weights: Epididymides, testes (in all animals sacrificed); adrenal glands, brain, heart, kidneys, liver, spleen, thymus (in 5 animals per sex/test group, females with litters only, same animals as used for clinical pathological examinations)

Statistics:

The following statistical tests were used (depending on the parameter): DUNNETT-test, KRUSKAL-WALLIS test, WILCOXON-test (one-side)

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:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY: No clinical signs or changes of general behavior, which may be attributed to the test substance, were detected in any male or female. Several male and female animals of dose group 3 (1000 mg/kg bw/d) showed salivation after treatment. This transient salivation for a few minutes immediately after each treatment was likely to be induced by the unpleasant taste of the test substance or by local irritation of the upper digestive tract. It is not considered to be a sign of systemic toxicity. There were no substance-related mortalities in any of the male and female parental animals in any of the groups. On premating day 12, one high dose F0 female (No. 137 - 1000 mg/kg body weight/day) was found dead after a gavage error.

BODY WEIGHT AND WEIGHT GAIN: comparable to the concurrent control group during the entire study period

FOOD CONSUMPTION: comparable to the concurrent control group during the entire study period

HAEMATOLOGY: No treatment-related changes among hematological parameters were observed. In males of test groups 2 and 3 (300 and 1000 mg/kg bw/d) absolute and relative eosinophil counts and additionally in males of test group 1 (100 mg/kg bw/d) relative eosinophil counts were increased. The values were within historical control ranges whereas the means of the control were at the low part of these ranges (absolute eosinophil counts: 0.07-0.18 Giga/L, relative eosinophil counts: 1.3-3.0 %). Therefore, these alterations were regarded as incidental and not treatment-related.

CLINICAL CHEMISTRY: In males of test group 2 (300 mg/kg bw/d) alanine aminotransferase (ALT) activities were lower, whereas in females of the same test group ALT activities were higher compared to controls. Additionally, in males of test group 2 (300 mg/kg bw/d) potassium values were lower compared to controls. All these values were changed not dose-dependently and therefore these alterations were regarded as incidental and not treatment-related. In males of test group 3 (1000 mg/kg bw/d) calcium levels were increased, but the means were within the historical control range (calcium: 2.49-2.76 mmol/L).
Therefore, this change was regarded as incidental and not treatment-related.

URINALYSIS: No treatment-related changes among urinalysis parameters were observed.

NEUROBEHAVIOUR: No test substance-related or spontaneous findings were observed in male and female animals of all test groups during the home cage observation as well as open field observations. Concerning the sensorimotor tests, no test substance-related findings in male and female animals of all test groups were observed. Any deviations from "zero values" were equally distributed between test substance-treated groups and controls or occurred in single animals only. Therefore, these observations were considered as being incidental. In addition, no treatment-related changes on motor activity data (summation of all intervals) was observed in the male and female animals of all dose groups in comparison to the concurrent control group. The statistically significantly decreased number of interrupted beams in high-dosed males (test group 3 - 1000 mg/kg bw/d) in interval 2, the statistically significantly increased number of interrupted beams in mid-dosed males (test group 2 - 300 mg/kg bw/d) in interval 6 and the statistically significantly increased number of interrupted beams in high-dosed females (test group 3) in interval 2 were considered as spontaneous in nature and not treatment related.

ORGAN WEIGHTS: When compared to the control group 0 (set to 100%), the mean relative and absolute liver weight was significantly increased in male animals of the high-dose group. All other mean relative and absolute weight parameters in males and all weight parameters in females did not show significant differences when compared to the control group 0. The increase in absolute and relative liver weights in test group 3 (1000 mg/kg bw/day) in male animals was considered to be treatment - related.

GROSS PATHOLOGY: One female animal that died showed a ruptured esophagus. All other findings occurred individually. They were considered to be incidental or spontaneous in origin and without any relation to treatment.

HISTOPATHOLOGY: NON-NEOPLASTIC: One animal showed rupture of the esophagus confirming the macroscopic diagnosis. All other findings occurred either individually or were biologically equally distributed over control and treatment groups. They were considered to be incidental or spontaneous in origin and without any relation to treatment.

HISTOPATHOLOGY: NEOPLASTIC: not examined

HISTORICAL CONTROL DATA: Yes

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: general, systemic toxicity (F0 generation)

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

GLP-conform study according to OECD guideline. The study was performed with the test article analogue.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In an OECD 422 study, the test substance analogue 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate was administered daily by gavage to groups of 10 male and 10 female Wistar rats to screen for potential repeated dose, reproductive and developmental toxicity. The animals were dosed throughout the study. For females this included two weeks prior to mating, the variable time of conception, the duration of pregnancy and at least four days after delivery. Males were dosed for a minimum of four weeks. Thereby, both sexes were exposed up to and including the day before scheduled kill with 100, 300, and 1000 mg/kg bw/d. Analyses confirmed the overall accuracy of the prepared concentrations and demonstrated the stability of the test substance in drinking water over a period of 7 days at room temperature. In the clinical examinations of the parental animals F0 no toxicologically-relevant adverse differences were caused by the test article analogue up to the limit dose of 1000 mg/kg bw/d. In the continuative investigations including the detailed clinical observation (DCO), the functional observational battery (FOB), and measurement of motor activity (MA) no significant differences to control were observed at any dose level. No treatment-related findings were observed during mating, gestation, delivery and lactation. Concerning clinical pathology including the analyses of red and white blood cells, coagulations parameters, enzymes, substrates, electrolytes, and minerals no treatment-related, adverse effects were observed up to limit dose (1000 mg/kg bw/d). Regarding pathology, the liver of male animals of test group 3 (1000 mg/kg bw/day) showed an increase in absolute (+11%) and relative (+12%) weights which was regarded to be adaptive and non-adverse in the absence of clinical and histopathological findings. All other pathological findings recorded were considered to be incidental in nature and not related to treatment. The test substance led to no treatment-related changes in the genital organs of males and females in the histopathological assessment.

The NOAEL for general, systemic toxicity is 1000 mg/kg bw/d for the F0 females and males.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance is not considered to be classified for repeated dose toxicity under Regulation (EC) No 1272/2008, as amended for the sixth time in Directive EC 605/2014.

Dangerous Substance Directive (67/548/EEC)

The available study is considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for repeated dose toxicity under Directive 67/548/EEC, as amended for the 31st time in Directive 2009/2/EG.

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