Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

ENVIRONMENTAL FATE PROPERTIES

Summary of degradation

Lanthanum trihydroxide is inorganic and hence the ready biodegradation and hydrolysis tests are not relevant. Abiotic and biotic degradation will not occur.

Volatilisation

Data on volatilisation are not available for the substance. Lanthanum trihydroxide is a solid and hence not volatile.

Distribution modelling

No distribution modelling data exist. Modelling is 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).

Summary and discussion of bioaccumulation

No bioaccumulation data are available on lanthanum trihydroxide but literature data provide information on the soluble salt lanthanum nitrate. BCF values of 1.2-13.8 were recorded after 29-45 days in; muscles skeleton and gills. Higher BCF values of 91-828 were recorded in internal organs. In all tissues equilibrium was reached or approached within the time period. Elimination in internal organs was shown to occur with a half life of 7 days. Lanthanum nitrate is therefore eliminated from fish and does not significantly bioaccumulate. Being much less water soluble, it is expected that lanthanum trihydroxide will be less bioavailable than the soluble salt tested. Hence bioaccumulation of Lanthanum trihydroxide is not expected.

Secondary poisoning

Bioaccumulation of lanthanum trihydroxide 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.