Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

ENVIRONMENTAL FATE PROPERTIES

Summary of degradation

Dineodymium tricarbonate 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. Dineodymium tricarbonate 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

In accordance with OECD Guideline 106 and EU Method C.18, the overall Kd range was 1.38 x 10³ to at least 6.10 x 10³, the overall Koc range was 1.33 x 10⁴ to at least 2.39 x 10⁵ and the overall log10 Koc range was 4.12 to at least 5.38 at 25 ± 2 °C.

Summary and discussion of bioaccumulation

No bioaccumulation data are available on insoluble salts of neodymium but literature data provide information on the soluble salt neodymium nitrate (see Section 5.3.1). A BCF value of 634 was recorded after 29 days, with BCF values reducing over time. The half-life for internal organs was calculated as 6.30 days. Neodymium nitrate is therefore eliminated from fish and does not readily bio-concentrate. By analogy to neodymium nitrate, dineodymium tricarbonate is unlikely to bio-accumulate, and furthermore being poorly water soluble it is expected to be less bio-available than the soluble salt tested.

Secondary poisoning

Bioaccumulation of dineodymium tricarbonate 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.