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Physical & Chemical properties

Dissociation constant

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Description of key information

The pKa of the acids ionisable constituents of Crude Tall Oil is predicted using a reliable freely-available method. 

Key value for chemical safety assessment

Additional information

No measured data for dissociation constant of Crude Tall Oil were available. The pKa value (normal conditions) was predicted using SPARC. The acids constituents of CTO were predicted to have pKa value of 4.59 - 4.80.

While the acids constituents (Fatty and Resin acids) group is ionisable, neutrals constituents such as alcohols are extremely weak acids and only dissociate under strongly basic conditions. In the range of pH usually considered relevant to the human body and environment, i.e. pH 2-9, acid constituents will ionise while the neutrals will be non-ionised. There is no need to conduct further testing.