Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 264-885-7
CAS number: 64417-98-7
Since no data are available on yttrium zirconium oxide, the aquatic
toxicity of the substance is evaluated using data for zirconium dioxide
(or other zirconium compounds) and yttrium oxide. Both zirconium dioxide
and yttrium oxide were found not to be toxic (acutely) to fish and
aquatic invertebrates. The available reliable studies were performed
according to internationally accepted guidelines and did not report any
acute adverse effects (mortality in fish, immobilization in daphnids) at
the limit test concentration of 100 mg/L. Based on this information,
yttrium zirconium oxide can also be concluded not to be toxic to fish
and aquatic invertebrates.
Adverse effects on algal growth were observed for several zirconium
substances (e.g., zirconium basic carbonate, zirconium dichloride oxide,
and a reaction mass of zirconium dioxide and cerium dioxide). However,
phosphate monitoring indicated that the observed effects are concurrent
with phosphate depletion and hence are due to phosphate deprivation. No
evidence has been found for direct toxic effects in algae upon exposure
to zirconium compounds. No data has been added to the dossier on yttrium
oxide or other yttrium substances because phosphate complexing behaviour
is also known for rare earth elements such as yttrium and Visual Minteq
(v3.0) modelling confirmed that whenever phosphate in the algal test
medium is in excess of yttrium, all yttrium will be lost from the
aqueous solution (hence no exposure), whereas whenever yttrium is in
excess, all phosphate is depleted from the test medium, and only
phosphate deprivation effects will be observed. Because the phosphate
complexing behaviour of zirconium and yttrium represents a technical
difficulty which cannot be resolved (e.g. by phosphate dosing during the
tests), it is not considered possible to obtain meaningful results from
algal growth inhibition experiments with yttrium or zirconium compounds.
The phosphate deprivation effect may affect algae in the environment
very locally at point discharges but this kind of effect is not
considered relevant for entire aquatic ecosystems.
Refinement of the hazard assessment through inclusion or generation of
long-term toxicity data (fish, aquatic invertebrates) is not considered
necessary because the substance is not classified for any hazard,
because the available acute toxicity data with zirconium dioxide (or
other zirconium compounds) and yttrium oxide did not reveal any relevant
adverse effects, and because yttrium zirconium oxide is anticipated to
have a limited water solubility.
Finally, toxicity to micro-organisms can be waived because of the
limited water solubility of the substance and the known complexation
behaviour of zirconium and yttrium (i.e., strong complexation with
phosphate and pH-dependent complexation with carbonate and hydroxide).
Micro-organisms in a STP are anticipated not to be exposed to yttrium
zirconium oxide due to this behaviour and limited water solubility.
Based on the available information yttrium zirconium oxide can be
concluded to be non-hazardous to aquatic organisms.
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.
På den här webbplatsen används kakor. Syftet är att optimera din upplevelse av den.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again