Urea, N,N''-1,4-cyclohexanediylbis-, trans-

Endpoint summary

Description of key information

In an acute oral toxicity study according to the Acute Toxic Class method, clinical signs were observed in the in female rats receiving 2000 mg/kg bw (impaired general state and piloerection in all animals), but not in the second group receiving 300 mg/kg. No mortality occurred in any of the dose groups. There were no macroscopic pathological findings in all animals sacrificed at the end of the observation period.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted according to OECD Guideline 423 and GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Strain: Crl:WI (Han) SPF
Age on day 0: Young adult females (approx. 10 – 11 weeks)
Supplier: Charles River Wiga GmbH, Germany
Arrival in testing facility: Acclimatization period of at least 5 days before the beginning of the experimental phase
Identification: cage cards and tail marking
Body weight on day 0: Animals of comparable weight (± 20% of the mean weight)

Room temperature/relative humidity: The animals were housed in fully air-conditioned rooms. Central air-conditioning guaranteed a range of 22°C ± 3°C for temperature and of 30 – 70% for relative humidity. There were no deviations from these ranges, which influenced the results of the study.
Air changes per hour: approx. 10
Day/night rhythm: 12h/12h
Type of cage: Makrolon cage, type III
Number of animals per cage: single housing
Feeding: VRF1(P); SDS Special Diets Services, 67122 Altrip, Germany
Drinking water: ad libitum
Bedding: H 15005-29; Ssniff, Spezialitäten GmbH (Experimental Animal Diets Inc., 59494 Soest, Germany)
Enrichment: Wooden gnawing blocks (Type NGM E-022) ; ABEDD® LAB & VET Service GmbH, Hasnerstraße 84/6; 1160 Wien – Austria

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5% in deionized water

Details on oral exposure:

Test item preparation: The test item preparations were produced for each test group shortly before administration by stirring with a high speed homogenizer (Ultra-Turrax) and a magnetic stirrer. Additionally, the homogeneity of the test item preparations during application was ensured by stirring with a magnetic stirrer.
Administration volume: 10 mL/kg bw
Concentration in vehicle: 200 mg/mL (2000 mg/kg bw group), 30 mg/mL (300 mg/kg bw group)
Reason for selection of vehicle: A good homogeneity in water could not be guaranteed, because the test item preparation was a suspension. Therefore, a 0.5% solution of CMC in deionized water was applied.
Form of application: Suspension

Doses:

2000 and 300 mg/kg bw

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

Fasting period: Feed was withdrawn from the animals at least 16 hours before administration, but water was available ad libitum.
Time of day of administration: In the morning
Observation period: 14 days
Selection of doses: A starting dose of 300 mg/kg bw was chosen in the first step with 3 animals. As no mortality occurred, 2000 mg/kg were administered to another group of 3 animals in the second step. Because no mortality occurred, 2000 mg/kg bw were administered to another group of 3 animals in the third step.
Body weight determination: Individual body weights shortly before administration (day 0), weekly thereafter and on the last day of observation.
Clinical observations: Clinical signs for each animal were recorded several times on the day of administration and at least once during each workday thereafter.
Mortality: A check for any dead or moribund animals was made at least once each workday; these records are archived by Bioassay.
Pathology: Necropsy with gross-pathology examination was performed on the last day of the observation period after sacrifice by CO2-inhalation in a chamber with gradually increasing concentrations.
Histology: No histological examinations were performed.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

No mortality occurred in all test groups.

Clinical signs:

other: Clinical signs in the first 2000 mg/kg test group revealed in all animals impaired general state and piloerection at hour 2 after administration only. No clinical signs were observed during clinical examination neither in the second 2000 mg/kg test group

Gross pathology:

There were no macroscopic pathological findings in the animals sacrificed at the end of the observation period (9 females).

Interpretation of results:

practically nontoxic

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study the median lethal dose of NM01 after oral administration was found to be greater than 2000 mg/kg bw in rats.

Executive summary:

In an acute oral toxicity study performed according to the Acute Toxic Class method, doses of 2000 and 300 mg/kg bw of the test item NM01 (preparations in 0.5% CMC-solution) were administered by gavage to three test groups of three fasted Wistar rats each (2000 mg/kg bw in 6 females, 300 mg/kg bw in 3 females). Clinical signs were observed in the first test group receiving 2000 mg/kg bw only (impaired general state and piloerection in all animals). No mortality occurred in any of the dose groups. There were no macroscopic pathological findings in all animals sacrificed at the end of the observation period. The mean body weight of the surviving animals increased within the normal range throughout the study period with one exception in the 300 mg/kg bw test group. One animal showed stagnation of body weight in the second week, which was, however, considered an unspecific effect.

Justification for classification or non-classification

As the oral LD50 in rats was found to be >2000 mg/kg, the classification criteria of the CLP regulation are not met.