Registration Dossier

Administrative data

Description of key information

1. Information on zirconium dioxide (CAS# 1314-23-4) 
Acute toxicity: oral
The LD50-value for acute oral toxicity determined via the acute class method in female Sprague-Dawley rats was > 5000 mg/kg.
2. Information on erbium oxide (CAS# 12061-16-4)
The oral LD50 of the test material was > 2000 mg/kg in rats. No signs of toxicity were observed at this dose.
3. Conclusion on erbium zirconium oxide
It is expected that the substance will have a similar toxicity profile as the read across substances zirconium dioxide and erbium oxide, more specifically that it is not expected to cause any adverse acute toxic effects after oral intake.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed

Additional information

1. Information on zirconium dioxide (CAS# 1314-23-4)

Acute toxicity: oral

One key study was identified. Acute toxicity was determined via the acute class method (OECD Guideline 423 and EU Method B1 tris) in female Sprague-Dawley rats. The LD50 value was > 5000 mg/kg.

2. Information on erbium oxide (CAS# 12061-16-4)

Acute toxicity: oral

The acute oral toxicity of erbium oxide 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.

3. Conclusion on erbium zirconium oxide

It is expected that the substance will have a similar toxicity profile as the read across substances zirconium dioxide and erbium oxide, more specifically that it is not expected to cause any adverse acute toxic effects.

Justification for classification or non-classification

1. Information on zirconium dioxide (CAS# 1314-23-4)

- Based on the available data and according to the DSD/CLP criteria zirconium dioxide should not be classified for acute toxicity via the oral route of exposure.

- No reliable data are available on the acute toxicity via the dermal route of exposure. Therefore no conclusion can be made on the classification for this exposure route.

- Based on available data (not included in this dossier, second route is not an Annex VII requirement) zirconium dioxide should not be classified for acute toxicity via the inhalation route of exposure.

2. Information on erbium oxide (CAS# 12061-16-4)

- Based on the available data and according to the DSD/CLP criteria erbium oxide should not be classified for acute toxicity via the oral route of exposure.

- No data are available on the acute toxicity via the dermal route of exposure. Therefore no conclusion can be made on the classification for this exposure route.

- Based on available data (not included in this dossier, second route is not an Annex VII requirement) erbium oxide should not be classified for acute toxicity via the inhalation route of exposure.

3. Conclusion on erbium zirconium oxide

As erbium zirconium oxide is expected to have similar properties as the read across substances zirconium dioxide and erbium oxide, it does not need to be classified as acutely toxic.