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No guideline laboratory studies for the determination of the adsorption potential of Lanthanum chloride were available. However, data determined in laboratory studies according to natural field situations, which calculated the Koc/Kp-values based on Lanthanum as element (La3 +), were available.

Moermond et al. (2001) derived Koc values for Lanthanum from laboratory assays with natural sediment and pore water taken from the Rhine-Meuse estuary, The Netherlands. The Koc values were calculated in a range of log 5.67 – log 6.92 depending on pH, salinity and addition of phosphate or fluoride and resuspension. Sneller et al. (2001) supported this scale of Koc values (log Kp 4.85 - 6.37), pointing out, that laboratory derived data are about one order of magnitude lower than field derived data. The authors stated that this difference was probably due to disturbance and subsequent oxidation of the sediment in the laboratory experiments, causing relatively high Lanthanum concentrations in the pore water. Generally, when evaluating the partitioning data one must keep in mind that pH, the presence of negative counterions and the concentration of dissolved organic carbon (DOC) in the (pore-) water strongly influence the concentration of Lanthanum in solution. When pH, DOC concentrations and negative counterion concentrations are high, a large part of the total dissolved Lanthanum concentrations may not represent ´true´ partitioning.

However, Lanthanum will be highly adsorbed at the sediment.