Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

ENVIRONMENTAL FATE PROPERTIES

Summary of degradation

Erbium oxide is inorganic and hence the biodegradation tests are not relevant. As this substance is highly insoluble into water, the hydrolysis assay is not relevant as well. Thus, abiotic and biotic degradation will not occur.

Volatilisation

Data on volatilisation are not available for the substance. Erbium oxide is a high melting point solid. Its vapour pressure is thus negligible and hence it is not volatile.

Distribution modelling

No distribution modelling data exist. Current modelling tools are not applicable to an inorganic substance such as this.

Summary of environmental distribution

Read across data are available for lanthanum oxide. An adsorption / desorption study has been conducted in 3 soils following the OECD 106 guideline. Kd values were 5451 to 216905 ml/g and Kocs were 230978 to 11476472 ml/g (mean 5480283 ml/g).

Read across data are also available for cerium carbonate. An adsorption / desorption study has been conducted in 3 soils following the OECD 106 guideline. Kd values were 11784 to >100843 ml/g and Kocs were 499332 to 5986256 ml/g (mean 3940404 ml/g).

Summary and discussion of bioaccumulation

No bioaccumulation data are available on dierbium trioxide but literature data provide information on the soluble nitrate salts of lanthanum, gadolinium and yttrium. BCF values of 1.3-105 were recorded after 29-45days in; muscles, skeleton, gills and internal organs.Therefore these compounds show no bioccumulation potential and, since dierbium trioxide is insoluble in water, it is expected that it will be less bioavailable than the soluble salts tested.

Secondary poisoning

Bioaccumulation of erbium oxide is not expected to occur. Hence no secondary poisoning risk exists.

Assessment of PBT/vPvB Properties - Comparison with the Criteria of Annex XIII

According to the Guidance on information requirements and chemical safety assessment, Chapter R.11: PBT assessment, “the PBT and vPVB criteria of Annex XIII to the regulation do not apply to inorganic substances”. Therefore the substance is not considered to require any further assessment of PBT properties.