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Physical & Chemical properties

Dissociation constant

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Description of key information

The test was waived based on 
1. the substance contains structurally related impurities
2. the main constituent is present for 88% (w/w) and is not expected to significantly differ in response from the impurities when applying the analytical methods commonly used for this test, i.e. spectrophotometric, titration or conductometric methods
3. the commonly used analytical methods may not be sensitive enough (test concentration < LOD) to result in reliable values
To give an indication of dissociation constants, these were calculated using the Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International). No acidic and two basic pKa of 3.41 and 2.27 were found.

Key value for chemical safety assessment

Additional information

In accordance with column 2 of REACH Annex IX, the dissociation constant test (required in section 7.16.) does not need to be conducted as it is scientifically not possible to perform the test for the following reasons:

1. the substance contains structurally related impurities

2. the main constituent is present for 88% (w/w) and is not expected to significantly differ in response from the impurities when applying the analytical methods commonly used for this test, i.e. spectrophotometric, titration or conductometric methods

3. the commonly used analytical methods may not be sensitive enough (test concentration < LOD) to result in reliable values

To give an indication of dissociation constants, these were calculated using the Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International). In the logarithm range of 1 - 14, for acidic and basic groups in the molecular structure of the test substance, no pKa.

were found for acidic groups and two pKa for basic groups: pKaof 3.41 and 2.27.