Zirconium oxide (ZrO2), erbium-doped

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2 March 1994 - 16 March 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dierbium trioxide

EC Number:

235-045-7

EC Name:

Dierbium trioxide

Cas Number:

12061-16-4

Molecular formula:

Er2O3

IUPAC Name:

Dierbium trioxide

Test material form:

solid: particulate/powder

Details on test material:

Appearance: pink powder
Storage conditions: room temperature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain: Sprague-Dawley ICO:OFA-SD (IOPS Caw)
- Age at study initiation: approximately 6 weeks
- Weight at study initiation (means): 164 ± 4g for the males, 161 ± 5 g for the females
- Fasting period before study: 18 hours before treatment; food was replaced approximately 4 hours after treatment
- Housing: animals were housed in groups of 4 to 7 animals of the same sex in polycarbonate cages (48 x 27 x 20 cm) covered with a stainless steel lid during the acclimatisation period and groups of 5 animals of the same sex during the study. Each cage contained graded, dust-free sawdust.
- Food consumption (e.g. ad libitum): ad libitum
- Water consumption (e.g. ad libitum): ad libitum filtered water contained in bottles
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 50 ± 20 % relative humidity
- Air changes (per hr): 13 cycles/hour of non-recycled and filtered air
- Photoperiod (hrs dark / hrs light): 12hr/12hr

In-life dates: From 02 to 16 March 1994

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: aqueous solution of methylcellulose at 0.5 %

Details on oral exposure:

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

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 animals per sex per dose

Control animals:

other: The body weight of the animals treated with the test material was compared to laboratory historical control data for animals dosed by the oral route.

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 material, for detection of possible treatment-related clinical signs and for mortality or signs of morbidity. Observations of the animals were made at least once a day for clinical signs and at least twice a day for mortality.
- Frequency of weighing: Animals were weighed just before administration of the test material and then on days 5, 8 and 15.
- Necropsy of survivors performed: yes (day 15). Animals were sacrificed by excess CO2 inhalation.
- Other examinations performed: macroscopic examination at necropsy (digestive tract, heart, kidneys, liver, lungs, pancreas, spleen and any other organ with obvious abnormalities).

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Mortality:

No deaths occured 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 sacrified at the end of the study revealed no apparent abnormalities.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to EU criteria.

Conclusions:

Under the experimental conditions of this study, the oral LD50 of the test material was > 2000 mg/kg in rats. No signs of toxicity were observed at this dose; the test material therefore requires no classification in accordance with EU criteria.

Executive summary:

The acute oral toxicity of the test material was evaluated in a limit test which was conducted in accordance with the standardised guideline OECD 401.

Groups of fasted, 6 week old Sprague-Dawley rats (5 per sex) were given a single oral dose of the test material in an aqueous solution of methylcellulose at 0.5 % at a dose of 2000 mg/kg bw (dose volume 10 mL/kg) and observed for 14 days.

No mortality and no clinical signs were observed during the study. The body weight gains of the treated rats were normal. No gross abnormalities were observed at necropsy.

The oral LD50 (males and females) was >2000 mg/kg bw and therefore the test material is not classified for acute oral toxicity in accordance with EU criteria.