Ytterbium (III) oxide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 March 2014 - 10 December 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ytterbium (III) oxide

EC Number:

215-234-0

EC Name:

Ytterbium (III) oxide

Cas Number:

1314-37-0

Molecular formula:

O3Yb2

IUPAC Name:

ytterbium(III) oxide

Test material form:

solid: particulate/powder

Details on test material:

Name (as on the report): Ytterbium(III) oxide
CAS no.: 1314-37-0
Batch no.: 11NYL17
Purity: 99.9%
Date of expiry: 9 December 2018

Specific details on test material used for the study:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: On the day of administration, the test item was freshly formulated at a concentration of 200 mg/mL (anhydrous form) with the vehicle.
- No correction factor was used in this study.

FORM AS APPLIED IN THE TEST (if different from that of starting material): formulation with a 0.5% aqueous solution of carboxymethylcellullose at a concentration of 200 mg/mL

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Italy s.r.l., San Pietro al Natisone (UD), Italy
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 7 weeks old
- Weight at study initiation: 236.10 g (average) at the start of the study (Day 1) (SD = 14.628)
- Fasting period before study: Yes. Food was removed from the cages overnight prior to dosing (Day -1) and was made available approximately 4 h after dosing.
- Housing: Up to 5 animals per cage. Polisulphone solid bottomed cages of 59.5x38x20 cm with nesting material provided into suitable bedding bags.
- Diet (e.g. ad libitum): Ad libitum (except for the dosing procedure). 4 RF 18 (Mucedola S.r.l., Via G. Galilei 4, 20019, Settimo Milanese (MI), Italy.
- Water (e.g. ad libitum): Ad libitum. Drinking water supplied to each cage via a water bottle.
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2°C
- Humidity (%): 55 +/- 15%
- Air changes (per hr): ca. 15-20
- Photoperiod (hrs dark / hrs light): 12 L:12 D - artificial (fluorescent tubes)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5% aqueous solution

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg
- Justification for choice of vehicle: not reported

Doses:

2000 mg/kg

No. of animals per sex per dose:

1 during preliminary test, 4 during main test

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations:
*Mortality and morbidity: twice daily
*Clinical signs: on dosing, approximately 0.5 h after dosing, approximately 2 h after dosing, approximately 4 h after dosing, and daily thereafter for a total of 14 days
*Body weight: at allocation (Day -1), on the day of dosing (Day 1), and on Days 2, 8 and 15
- Necropsy of survivors performed: Yes, on all animals (gross necropsy examination for both external and internal abnormalities, with particular attention to the gastro-intestinal tract). Animals were sacrificed by carbon dioxide narcosis.

Results and discussion

Preliminary study:

During the observation period, no mortality occurred and no clinical signs were noted in the single female animal dosed at 2000 mg/kg. Therefore, the dose for the main study was also 2000 mg/kg.

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No mortality was observed in the 4 animals treated at 2000 mg/kg.

Clinical signs:

other: No clinical signs were observed in the 4 animals treated at 2000 mg/kg.

Gross pathology:

No abnormalities were observed at the necropsy examinations.

Other findings:

No other findings reported.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the study, the acute oral LD50 value of ytterbium oxide was found to be above 2000 mg/kg bw in female Sprague Dawley rats. No mortality and no clinical signs were observed in the treated animals. According to these results, ytterbium oxide needs not to be classified according to CLP criteria.