Registration Dossier
Registration Dossier
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EC number: 937-221-5 | CAS number: -
Toxicity to microorganisms
Administrative data
Link to relevant study record(s)
Description of key information
The 3-hour NOEC of the reaction mass of neodymium carbonate and praseodymium carbonate to activated sludge microorganisms was ≥ 1000 mg/L. The 3-hour EC20, EC50 and EC80 were clearly higher than 1000 mg/L, based on respiration rate. Hence, the reaction mass of neodymium carbonate and praseodymium carbonate has no toxic effect on the respiration rate of activated sludge microorganisms.
Key value for chemical safety assessment
Additional information
One experimental study, scored as Klimisch 1 and selected as key study, showed that the reaction mass of neodymium carbonate and praseodymium carbonate had no toxic effect on the respiration rate of activated sludge microorganisms (Roulstone P., 2013), therefore warranting no classification.
This result was further corroborated by two other toxicity studies, scored as Klimisch 2 (due to read-across) and flagged as supporting study, on analogues of the reaction mass: dicerium tricarbonate and praseodymium(III,IV) oxide (Grutzner I., 2006; Bayliss C., 2013). In these studies performed on activated sludge microorganisms, 3-h EC50 (based on respiration rate) were systematically greater than the nominal concentration of 1000 mg/L.
Reaction mass of neodymium carbonate and praseodymium carbonate |
Dineodymium tricarbonate |
Dipraseodymium tricarbonate |
Dicerium tricarbonate |
Neodymium oxide |
Praseodymium(III,IV) oxide |
|
Toxicity to activated sludge microorganisms - EC50 (OECD 209, GLP) |
> 1000 mg/L |
no data |
no data |
> 1000 mg/L |
no data |
> 1000 mg/L |
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