Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Currently viewing:

Administrative data

Description of key information

Additional information

No reliable data were available for the endpoints toxicity to soil macroorganisms except arthropods, toxicity to terrestrial arthropods and toxicity to soil microorganisms. These endpoints are waived based on the negligible bioavailability of zirconium in soil. Based on analysis of thermodynamic stability of aqueous zirconium species, the concentration of free Zr4+ ions under environmental conditions is barely detectable. Ionic zirconium (Zr4+) at relevant pH conditions (pH 7 - 8) of aquatic and terrestrial environments will rapidly transform to zirconium-oxide and -hydroxide complexes, precipitate and not be bioavailable to organisms. In view of the very low water solubility of ZrO2, it is not expected that Zr is available to terrestrial organisms. This is confirmed by a plant growth study with both insoluble and soluble Zr compounds, which did not show any adverse effects. Furthermore, ZrO2 is not classified as hazardous for the aquatic environment. In conclusion, there is currently no reason that triggers the performance of additional studies with soil organisms for the refinement of hazard conclusions or chemical safety assessment for zirconium substances.

Toxicity to terrestrial plants:

Ferrand (2006) performed a plant growth study with zirconium oxychloride according to EPA OPPTS guideline 850.4230. In this study, tomato and pea seedlings (ca. 21 days old) were exposed for 7 days to two different soils contaminated with either a soluble Zr compound (ZrOCl2 or Zr acetate) or an insoluble Zr compound (Zr(OH)4). In none of the experiments adverse effects were observed on root or shoot fresh weight of the plants. Unbound NOEC values were obtained for all experiments. The lowest unbound NOEC was >= 264 mg Zr/kg dw for the calcareous soil (164 mg Zr/kg background) amended with 100 mg Zr/kg ZrOCl2 or Zr acetate. The highest unbound NOEC was >= 703.4 mg Zr/kg dw for the acidic soil (417.4 mg Zr/kg background) amended with 286 mg Zr/kg Zr(OH)4. Because ZrO2 is also a highly insoluble Zr compound and background Zr in soils is also assumed to be present as insoluble Zr compounds such as ZrO2 and ZrSiO4, the unbound NOECs for the experiments with Zr(OH)4 are more relevant for ZrO2.

Toxicity to birds:

No reliable data are available for this endpoint. Testing is waived based on following justification: based on analysis of thermodynamic stability of aqueous zirconium species, the concentration of free Zr4+ ions under environmental conditions is barely detectable. Ionic zirconium (Zr4+) at relevant pH conditions (pH 7 - 8) of aquatic and terrestrial environments will rapidly transform to zirconium-oxide and -hydroxide complexes, precipitate and not be bioavailable to organisms. Furthermore, ZrO2 is not classified as hazardous for the aquatic environment and the bioaccumulation potential of ZrO2 is very low. Therefore, members higher in the food chain are considered not relevant for further examination. In conclusion, there is currently no reason that triggers the performance of studies with birds for the refinement of hazard conclusions or chemical safety assessment for zirconium substances.