Registration Dossier

Environmental fate & pathways

Hydrolysis

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Description of key information

The test substance is stable at pH 4, 7 and 9 at 50°C: it has a half-life period longer than one year at 25 °C at pH 4, 7 and 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 catalysed 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.

For the substance, also confirmed by calculation with HYDROWIN 2.0, it can be estimated that hydrolysis does not occur because there is not hydrolysable groups in any of the structures.

Hydrolyzable 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

A test has been conducted according to internationally accepted testing guidelines and according to GLP on an analogous substance of the Stilbene Fluorescent Whitening Agent category, group 3, CAS 16470 -24 -9, for which a reliable Hydrolysis study has been reported. The two substances ( 16470-24-9 and 68971-49-3) are very similar and are constituted by the same functional groups, with the difference that 16470-24-9 is tetrasulphonated intead than hexasulphonated, sodium salt. The difference in sulphonation can have an influence on water solubility, but not on the hydrolysation potential, since both substances have no hydrolysable groups in the chemical structure. Quantity and chemical identity of the impurities has no influence on the possibility of Read Across for this end point. For further details refer to the Category Justification Report in section 13 of this dossier