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Physical & Chemical properties

Partition coefficient

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Description of key information

The partition coefficient is defined as the ratio of the equilibrium concentrations of a dissolved substance in a two-phase system consisting of two largely immiscible solvents. In this study, the partition coefficient is the ratio of the measured concentration of the test item in the n-octanol phase and the measured concentration of the test item in the water phase.
Experimental value for test item solubility in n-octanol at 20°C: 0.60 ± g/l 0.08g/l
Experimental value for test item water solubility at 20°C: 187.45 g/l ± 14.98 g/l
Calculated partition coefficient : 0.0032
Calculated log Kow : – 2.50 ± 0.09

Key value for chemical safety assessment

Log Kow (Log Pow):
-2.5
at the temperature of:
20 °C

Additional information

The test item is a surfactant product (surface tension = 33.2 mN/m ± 0.1 mN/m at 21.0 ± 0.1 °C) so the shake flask and HPLC methods (E.U A8) can’t be used. In this case, the partition coefficient is calculated by the ratio of solubilities of test item in n-octanol and in water, determined with the flask method. The method used for this determination is consistent with to A.6: “Water solubility”, May 2008 and to the OECD Guidelines n° 105: “Water solubility”, adopted July, 27, 1995. No deviations form the guidelines were observed during the test.