Lanthanum(3+) acetate

Endpoint summary

Additional information

Terrestrial toxicity

Only supporting information (mixture toxicity) was identified for the endpoints toxicity to terrestrial arthropods and soil macroorganisms other than arthropods. No significant adverse effects were observed in these studies.

For terrestrial plants, the endpoint is covered using two studies in a weight of evidence approach. The study of Hu et al. (2006) exposed maize seedlings (Zea mays) to La(NO3)3 in a natural Chinese soil and yielded a 14-d NOEC of 250 mg La/kg soil dw (added lanthanum) for root elongation and root dry weight and a 14-d NOEC of 500 mg La/kg soil dw (added lanthanum) for shoot dry weight. The study of Zeng et al. (2006) exposed rice seedlings (Oryza sativa) to LaCl3 in red soil and paddy soil and reported a 68-d NOEC and EC50 of 46.3 and 323.02 mg La/kg soil dw, respectively, in red soil, and a 68-d NOEC and EC50 of 56.1 and 646.6 mg La/kg soil dw, respectively, in paddy soil. The NOEC and EC50 obtained in red soil were selected as key values for this endpoint. They correspond to 105 and 735 mg La(CH3COO)3/kg soil dw.

Two toxicity studies (Schulz, 2010; Lemnitzer, 2010) were used in a weight of evidence approach to cover the endpoint of toxicity to soil microorganisms. The lowest NOEC and EC50 were reported by Lemnitzer (2010) for the toxicity of lanthanum (added as LaCl3) on microbial nitrate formation in soil according to OECD guideline 216.The 28-d NOEC and EC50 were determined to be 283 and > 566 mg La/kg soil dw, respectively. These values were considered as key values and correspond to a NOEC and EC50 of 644 and > 1288 mg lanthanum triacetate/kg soil dw.

A single key study (Zohravi, 2006) was used to cover the endpoint toxicity to birds. This study yielded 28-d NOECs for both mortality and growth of Japanese quails of >= 44 and >= 57 mg La/kg diet when supplying lanthanum as La(CH3COO)3 or LaCl3, respectively. These values correspond to >= 100 and >= 130 mg lanthanum triacetate/kg diet.