lambda4-cerium(4+) zirconium(4+) tetraoxidandiide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 16-OCT-1995 to 08-MAR-1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of cerium dioxide and zirconium dioxide

EC Number:

909-709-8

Molecular formula:

(Ce, Zr)O2

IUPAC Name:

Reaction mass of cerium dioxide and zirconium dioxide

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Poudre catalytique à base d'oxyde de cérium et d'oxyde de zirconium (OBD 30)
- Substance type: multi-constituent substance
- Physical state: yellow powder
- Further information on test material confidential

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Iffa Credo, 69210 L'Arbresle, France
- Age at study initiation: 6 weeks old
- Weight at study initiation: 173 +/- 4 g for the males, 145 +/- 5 g for the females
- Fasting period before study: 18 hours, they were then given food 4 hours after treatment
- Housing: The animals were housed in groups of 4 to 7 animals of the same sex in polycarbonate cages (48x27x20 cm) during the acclimatisation period and groups of 5 animals of the same sex during the study.
- Diet (e.g. ad libitum): free access to AO4 C pelleted diet (U.A.R., 91360 Villemoisson-sur-Orge, France) except in fasting period
- Water (e.g. ad libitum): drinking water filtered by a Millipore membrane (0.22 micron), ad libitum
- Acclimation period: at least 5 days before the beginning of the study

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +/- 2°C
- Humidity (%): 30 to 70% relative humidity
- Air changes (per hr): about 12 cycles/hour of filtered, non recycled air
- Photoperiod (hrs dark / hrs light): 12hr/12hr

IN-LIFE DATES: From: 14 nov 1995 To: 28 nov 1995

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: aqueous solution of methylcellulose at 0.5%

Details on oral exposure:

VEHICLE
The vehicle used was an aqueous solution of methylcellulose at 0.5%:
- water for injections, batch N° 5842 (Laboratoire Fresenius, 92316 Sèvres, France)
- methylcellulose, batch N° 15H0241 (Sigma, 38297 Saint-Quentin-Fallavier, France)

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg

DOSAGE PREPARATION:
On the day of the treatment, the test substance was ground using a mortar and pestle, then was suspended in the vehicle.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

DETAILS ON STUDY DESIGN
- Duration of observation period following administration: 14 days
- Frequency of observations: The animals were observed frequently after administration of the test substance and at least once a day for clinical signs.
- Frequency of weighing: Animals were weighed just before administration of the test substance and then on days 1, 8 and 15.
- Necropsy of survivors performed: yes on day 15
- Other examinations performed: macroscopic examination at necropsy (digestive tract, heart, kidneys, liver, lungs, pancreas, spleen and any other organ with obvious abnormalities)

Statistics:

no data

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

No deaths occurred during the observation period.

Clinical signs:

other: No clinical signs were observed during the study.

Gross pathology:

The macroscopic examination of the main organs of the animals sacrificed at the end of the study revealed no apparent abnormalities.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the experimental conditions of this study, the oral LD50 of the reaction mass of cerium dioxide and zirconium dioxide was higher than 2000 mg/kg in rats. No signs of toxicity were observed at this dose.

Executive summary:

The reaction mass of cerium dioxide and zirconium dioxide has been tested for acute oral toxicity in Sprague Dawley rats, according to OECD guideline No. 401 and in compliance with Good Laboratory Practices. The test article, suspended in 0.5% aqueous methylcellulose, was administered as a single dose of 2000 mg/kg to a group of 5 males and 5 females, at a dosing volume of 10 mL/kg. Following treatment, mortality, clinical signs and body weight were recorded for a two-week observation period. On day 15, the animals were euthanatised and necropsied.

 

No deaths occurred and no clinical signs were observed in this study. Body weight gain was not affected by treatment. At necropsy, a macroscopic examination revealed no abnormality .

 

As the minimal lethal dose was found to be higher than 2000 mg/kg, the reaction mass of cerium dioxide and zirconium dioxide is not classified according to the criteria of EU-CLP Regulation 1272/2008.

This acute oral study is classified as acceptable. It does satisfy the guideline requirements for an acute oral study (OECD 401) in rats.