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Description of key information

In a 90-day dietary study with lanthanum carbonate in rats no treatment related adverse effects were obseved up to the highest dose tested (14000 ppm or 974 mg/kg bw/d for males and 1480 mg/kg bw/day for females) corresponding to a NOAEL > 525 mg/kg bw/d for males and > 799 mg/kg bw/day for females based on Lanthanum oxide.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
Study duration:

Additional information

Repeated dose toxicity summary

No study is available for Lanthanum oxide. For the analogous substance lanthanum carbonate a reliable 90-day oral feeding study (according to OECD guideline 408 and under GLP) has been conducted. Due to the comparably low water solubility of the two substances, supported by the available toxicokinetic information this study can reasonably be used for the assessment of lanthanum oxide as well. Further studies on lanthanum oxide are therefore not regarded as scientifically necessary and are not recommended under animal protection considerations.


Repeated dose toxicity was analyzed in a reliable subchronic feeding study with Lanthanum carbonate octahydrate performed under GLP according to OECD guideline 408. Groups of five male and female Wistar rats received nominal doses of 1400, 2400 and 14000 ppm for 90 days in the diet. In addition to the guideline protocol neurobehavioral tests as well as immunotoxicological examinations were performed in satellite groups. With the exception of single incidental findings no treatment- related adverse effects were observed. Therefore, the NOAEL was found to be 14000 ppm Lanthanum carbonate octahydrate corresponding to 6440 ppm Lanthanum or 7553 ppm La2O3. Based on the daily food consumption the NOAEL based on lanthanum carbonate was ≥ 974 mg/kg bw/d for males (448 mg La/kg bw/d, or 525 mg/kg bw/d La2O3) and ≥ 1480 mg/kg bw/d for females (681 mgLa/kg bw/d or 799 mg/kg bw/d La2O3) respectively, i.e. greater than the highest dose tested in the study.

Justification for classification or non-classification

Based on a NOAEL of > 525 mg/kg bw/day calculated as La2O3, with no treatment related effects observed in a 90 -day dietary study in rats with the analogous substance lanthanum carbonate, no classification for repeated dose toxity is warranted.