Dilanthanum tricarbonate

Endpoint summary

Description of key information

Oral: 
LD50 (rats) > 30404 mg/kg bw Lanthanum carbonate
Inhalation: 
LC50 (rats) > 4509 mg/m³ Lanthanum carbonate
Dermal: 
LD50 (rabbit) > 1924 mg/kg bw Lanthanum carbonate

Additional information

Oral

The acute oral toxicity of Lanthanum carbonate monohydrate was tested according to the Guideline of the Department of Transportation (D.O.T), Code of Federal Regulations, Title 49, Part 173 (Ward, 1976). The test substance was administered to rats in a limit test at a dose of 31600 mg/kg bw, mortality and clinical signs were observed for 48 h. Since no mortality occurred and no clinical signs were detected, the LD50 was stated as greater than 30404 mg Lanthanum carbonate/kg bw.

Furthermore, in an acute oral toxicity study according to OECD 423, a first group of 3 females was given a single oral dose of Lanthane carbonate (containing water) as such in PEG 300 at a dose of 2000 mg/kg bw and observed for 14 days (Ott, 2005). As no death and no clinical signs were observed, a second group of 3 females was tested under the same test conditions. No mortality and only minor clinical signs (slightly ruffled fur and hunched posture observed up to 3 days of the study) were observed in the second group of animals. The LD50 was stated as greater than 2000 mg/kg bw (corresponding to 1367 mg Lanthanum carbonate/kg bw).

 

Inhalation

The acute inhalation toxicity of Lanthanum carbonate octahydrate was investigated in a GLP-study according to OECD 403 (Pauluhn, 2005). 5 male and 5 female rats were exposed nose-only for 4 hours to the test substance. The measured test concentration of the limit test was 5928 mg/m³ (according to 4509 mg Lanthanum carbonate/m³), the MMAD of the particles was 6.93 µm. Mortality did not occur, but all rats of the exposure group showed macroscopic alterations of the lung. The most prominent changes included gray-red dislocations and no collapse of the lung upon opening the thoracic cavity (consolidation). After necropsy, the lungs from some rats were cut and whitish, highly viscous deposits were observed. The LC50 was stated as greater than 4509 mg Lanthanum carbonate/m³.

 

Dermal

The acute dermal toxicity of Lanthanum carbonate monohydrate was tested according to the Guideline of the Department of Transportation (D.O.T), Code of Federal Regulations, Title 49, Part 173 (Ward, 1976). After acute dermal application of 2000 mg/kg bw to the intact skin of rabbits for 24 h under occlusive conditions, no signs of systemic toxicity were observed after an observation time of 48 h. Not even erythemas or edemas were observed 24 and 48 hours after exposure. Therefore, the LD50 was determined as higher than 2000 mg/kg bw, which corresponds to higher than 1924 mg Lanthanum carbonate/kg bw.

 

Justification for classification or non-classification

The data on acute toxicity oral, dermal and inhalative exposure are conclusive but not sufficient for classification according to the criteria of Directives 67/548/EEC (DSD) and 1272/2008/EC (CLP).