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Environmental fate & pathways

Hydrolysis

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Description of key information

Half-life greater then one year at 25 °C and pH values of 4, 7, 9 

Key value for chemical safety assessment

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

Additional information

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.

Hydrolysable organic groups are those ones that can react with water like Esters, Anhydrides, Amides, Carbammates, Nitriles, Cyanates, Epoxides, Halomethanes, Alkylhalides, Urea.

Read across substance "Similar substance 01" undergoes slow hydrolysis, with a half-life greater then one year at 25 °C and pH values of 4, 7, 9. At 50°C and after 2.4 hours only around 1% of the sample was hydrolysed at pH 4, 7, 9.

Therefore, hydrolytic degradation of Direct Red 23 is unlikely given that the abovementioned tests on DR262 indicate the lack of hydrolysis under any conditions.