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Environmental fate & pathways

Adsorption / desorption

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Description of key information

Cyclohexylamine has a measured log Koc of 3.4 at 25 °C and a pH of 6.7 (Currenta , 2010). According to Swann et al. (1993) cyclohexylamine has a high potential to sorb on soil. 

Key value for chemical safety assessment

Additional information

In case more than 10 % of the test item is dissociated at pH 6, a second test has to be performed at a pH where the test item is undissociated. The pKa value of the test item Cyclohexylamine accounts for 10.68 (Perrin, 1965) having the nonionic form solely at pH values approximately greater 11. As the prescribed analytical column for the HPLC method is not suitable for strong basic conditions (outside operating range), the measurement was performed at pH 6 only.

Based on the dissociation constant of 10.68 (Perrin, 1965), the substance will, under environmental relevant conditions (pH 4 to 9), be present solely in the protonated form. Therefore, the measured logKoc reflects the properties of the protonated form rather than the neutral species and thus the properties of the environmental relevant species.