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Environmental fate & pathways

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Adsorption / desorption:

Based on the available studies for the target substance Fluorescein sodium (Cas no.518-47-8) are summarized as fallowed:

From peer reviewed journal (Bull. Environ. Contam. Toxicol. (1998) 61:426-432) study investigated the dissipation and fate of phloxine B and uranine in water and sediment in the spill site. Distribution coefficients (Koc) of phloxine B and uranine were determined.

It was observed that adsorption coefficients of uranine were higher in soil than in sediments although the organic carbon content of the sediment is higher than soil. Uranine was not detected in the sediment samples after 284 days. Uranine was less persistent compared to Phloxine B.

The adsorption coefficient (Koc) value of Uranine in soil was found to be 88.81along with percentage organic carbon of 3.10%.While same test condition for sediment indicate the adsorption coefficient (Koc) value of Uranine as 69.43 along with percentage organic carbon of 3.94%.

While the objective of the other study was to utilize batch studies to determine the adsorptive characteristics of fluorescein with a low organic content alluvial aquifer sand.

Inspection of the adsorption isotherm for fluorescein indicates that it demonstrated linearity at low concentrations with non linearity experienced at higher concentrations. The koc value of 120 cm3/g for fluorescein was obtained in the batch equilibrium studies. The Freundlich adsorption isotherm could not be estimated due to the discontinuous nature of the adsorption isotherm and background fluorescence observed at higher concentrations. (Groundwater, Volume 29, Issue 3, May 1991, Pages 341–349)

Thus overall experimental studies indicate that the test substance Fluorescein sodium (uranine) have tendency to adsorbed higher in soil than in sediments.