Registration Dossier

Physical & Chemical properties

Partition coefficient

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The partition coefficient calculated by EpiSuite for Vat Indigo Potassium Salt is Log Kow(version 1.67 estimate): -1.10
The partition coefficient for the oxidised, environmentally stable form Indigo is Log Kow: 2.7

Key value for chemical safety assessment

Log Kow (Log Pow):
-1.1

Additional information

The test substance is synthesized and handled as an aqueous potassium hydroxide solution (pH 13) only under inert gas atmosphere. It is instable in an aqueous phase at neutral pH or as solid material on air and oxidises rapidly to indigo CAS 482-89-3. The determination of the partition coefficient of indigo vat potassium salt is hence not possible.

The data on indigo is as follows:

Determined experimentally from solubilities: log Pow >1.4 at 23°C

Determined experimentally by HPLC: log Pow 2.7 at 23°C

Calculated by KOWWIN: 3.11

Experimental KOWWIN: 3.72

The partition coefficient calculated by EpiSuite for Vat Indigo Potassium Salt is the following:

Log Kow(version 1.67 estimate): -1.10