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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Adsorption to solid soil phase is not expected.

Key value for chemical safety assessment

Additional information

A calculated logKoc of 1.56 is available (BASF AG, SRC PCKOC v1.66, 2007). This value refers to the uncharged molecule (pKa value: 10.45 - 10.86). This pKa value indicates that the molecule will exist primarily as a cation in the environment and cations generally adsorb stronger to soils containing organic carbon and clay than their neutral counterparts. Hence, the PCKOC-model may underestimate adsorption to organic carbon since it does not consider the ionic structure of the molecule. Under environmental conditions (pH from 5 to 9) the test substance is almost completely present in its charged form (as calculated by the formula % ionised = 100/(1+10(pKa - pH)): 97% at a pH of 9, 100% at lower pH values). In a calculation conducted according to a publication by Franco & Trapp, 2008 using the parameters pKa = 10.45 and log Pow = 0.4 a log Koc value of 4.39 was determined.