Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Between 6 November 2012 and 6 December 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)
Deviations:
no
Qualifier:
equivalent or similar to
Guideline:
EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)
Deviations:
no
GLP compliance:
yes
Test type:
fixed dose procedure
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
- Name as mentioned in the study report: cerium ammonium nitrate

Test animals

Species:
rat
Strain:
Wistar
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Oxon, UK
- Age at study initiation: 12 weeks
- Weight at study initiation: female at 2000 mg/kg: 153 g at day 0; range for females at 300 mg/kg: 152 to 160 g
- Fasting period before study: Animals had free access to food and drinking water except for overnight immediately prior to dosing
- Housing: Animals were housed in suspended solid-floor polypropylene cages furnished with wood flakes in groups of up to four animals.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25 °C
- Humidity (%): between 30 and 70%
- Air changes (per hr): at least 15 changes per hour.
- Photoperiod (hrs dark / hrs light): 12 hours light / 12 hours darkness

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Remarks:
distilled water
Details on oral exposure:
The test item formulations were not adjusted for the purity of the test item. For the purpose of the study the test item was freshly prepared, as required, as a solution in distilled water.
The test item was formulated within two hours of being applied to the test system. It is assumed that the formulation was stable for this duration.

Doses:
Sighting test: 2000 mg/kg and 300 mg/kg
Main test: 300 mg/kg
No. of animals per sex per dose:
one female at 2000 mg/kg
five females at 300 mg/kg
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were made 30min, 1, 2, and 4 hours after dosing and then daily for up to 14 days. Morbidity and mortality checks were made twice daily. Individual bodyweights were recorded on day 0 (the day of dosing) and on days 7 and 14 or at death.
- Necropsy of survivors performed: yes: at the end of the observation period the surviving animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.


Statistics:
No data

Results and discussion

Preliminary study:
The animal treated at a dose level of 2000 mg/kg was found dead one day after dosing. Signs of systemic toxicity noted in the animal treated at a dose level of 2000 mg/kg on the day of dosing were hunched posture, pilo-erection and ptosis. Haemorrhage and epithelial sloughing of the gastric mucosa was noted at necropsy. No deaths or signs of systemic toxicity were observed at a dose level of 300 mg/kg.
Effect levels
Sex:
female
Dose descriptor:
LD50
Effect level:
300 - 2 000 mg/kg bw
Based on:
test mat.
Mortality:
There were no deaths at a dose level of 300 mg/kg.
Clinical signs:
There were no signs of systemic toxicity at a dose level of 300 mg/kg.
Body weight:
All animals at 300 mg/kg showed expected gains in bodyweight.
Gross pathology:
Raised limiting ridge of the stomach was noted at necropsy of one animal treated at a dose level of 300 mg/kg. No abnormalities were noted at necropsy of four animals.
Other findings:
No data

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
Conclusions:
The acute oral LD50 was estimated to be in the range of 300 - 2000 mg/kg bw. The test substance is therefore considered classified as category 4 acute oral toxicant according to CLP Regulation.