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Environmental fate & pathways

Hydrolysis

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Description of key information

ITC 288/S is considered to be hydrotically stable

Key value for chemical safety assessment

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

Additional information

One reliable key study is available, where the hydrolysis of ITC 288/S has been determined according the EU method C.7 of the Commission directive 84/449/EEC and the GLP.

A preliminary test was performed at 50°C at pH 5, 7 and 9.

The concentrations were analysed by Ion Chromatography.It has been observed that, for component n=2, the distribution and number of peaks were altered quite markedly by changed pH, concentration or with time. The explanation of the observed changes was that the fours species seen in the chromatogram are in equilibrium in the liquid phase. However, in the solid phase, this equilibrium has been disturbed such that, on dissolution, the system starts to re-equilibrate. The rate at which equilibrium is re-established and possibly even the position of that equilibrium are pH dependent.

It has been therefore considered that the apparent decrease in the concentration of 1 -phosphonobutane-1,2,3,4 -tetracarboxylic acid hexasodium salt was not due to hydrolysis.

The hydrolysis of both components n=1 and n=2 in ITC 288/S was monitored and the results have been expressed individually as well as in terms of ITC 288/S itself.

The preliminary test showed less than 10% of hydrolysis. Based on this preliminary result, ITC 288/S is considered to be hydrotically stable and no additional testing is required.

As no information on the recovery, the repeatability and sensitivity of the analytical method is reported, this study is considered as reliable with restrictions.