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EC number: 231-176-9
CAS number: 7440-67-7
One study is available for acute toxicity via the oral route of exposure (according to OECD 423): the LD50 is > 2000 mg/kg (rat) and the LD50cut off is > 5000 mg/kg.No reliable data is available for acute toxicity via the inhalation route of exposure. As Zr powder is pyrophoric, it is not technically possible to generate an inhalable test atmosphere. Based on the same behaviour and toxicological effects, a read across with ZrO2 is performed. No toxic effect is observed in the available study, the LC50 is therefore > 4.3 mgZrO2/L or >3.18 mg eq Zr/L
One reliable test is available to
assess the oral acute toxicity of Zr (Klimisch 1). This study has been
performed according to the OECD guideline 423 where the rats exposed
received an unique dose of 2000 mg/kg Zr. No mortality was observed
during the test and during the 14 days of observation. Zr is not toxic,
its LD50 is higher than 2000 mg/kg and the LD50cut off is higher than
For inhalation acute toxicity, as this
test is technically impossible, a read across with ZrO2 is realised.
Indeed, according to the REACh recommendations, a read across could be
used for substances with similar behaviour and toxic effects in the
organism. An OECD guideline 436 was available: 3 male and 3 female were
exposed nose-only to 4.3 mg/L of ZrO2 for 4 hours. The mean mass median
aerodynamic diameter was 2 µm (+/- 1.75 µm). With this particle size,
ZrO2 could reach lower parts of respiratory tract, like the bronchioles.
No mortality was observed during the test, all animals were considered
clinically normal and no macroscopic findings were noted at the
scheduled necropsy. All animals lost weight from study day 0 to 1; one
male showed a slight loss of weight between day 1 and 3.The
CL50 equivalent for Zr was 3.18 mg/L.
Based on the available oral and
dermal data, the substance was not classified under the CLP
Regulation 1272/2008 and the directive Classification and Labelling
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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