Registration Dossier

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The organic carbon partition coefficient (Koc) for naphthalene-1,5-disulphonic acid was predicted using the QSAR calculation of the Estimation Program Interface (EPI) Suite v 4.11. The Koc was estimated to be 2.542 L/kg (logKow method), and 758.3 L/kg (MCI method). The results relate to the unaffected molecule of the substance as any decomposition (e.g. hydrolysis) of the substance is not taken into account by the program.

Discussion: Under environmentally relevant pH (1-9), the substance presents mainly as dissociated form and the organic part is negatively charged. Soil and sediment particles are normally negatively charged; and hence the adsorption coefficient (log Koc) of ionised substance to soil should be lower than the one of undissociated form. Therefore the estimated log Koc of undissociated substance can be used as a worst case.

Key value for chemical safety assessment

Additional information