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Environmental fate & pathways

Hydrolysis

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Description of key information

Not hydrolysable

Key value for chemical safety assessment

Half-life for hydrolysis:
1 yr
at the temperature of:
25 °C

Additional information

A single screening study (VUOS, 2011) was performed on a similar acid azo dye, showing that less than 10% of the test substance hydrolyses within 5 days period.

Hydrolysis is a common degradation route in the environment, namely the reaction of a substance with water with a net exchange of the X group with an OH at the reaction centre such that RX + H2O → ROH + HX. Hydrolysis is often dependent upon pH as the reaction is commonly driven by hydrogen or hydroxide ions. Hydrolysis kinetics are usually determined experimentally and should be used to consider the test type and whether parent or degradation product should be tested.

In the case of the Direct Brown 44, it can be estimated that hydrolysis does not occur because there are not hydrolysable groups in any of the structures.

Hydrolysable organic groups are in fact those groups that can react with water like Esters, Anhydrides, Amides, Carbammates, Nitriles, Cyanates, Epoxides, Halomethanes, Alkylhalides, Urea and none of these groups are present within the substance or their impurities.