Sodium dimethyl 5-sulphonatoisophthalate

Hydrolysis

Description of key information

t1/2 at pH 1.2: 31 at 37°C; t1/2 at pH 7: 268, 69 and 15 days at 15, 25, and 35°C, respectively; t1/2 at pH 9: 5,1 and 0.4 days at 15, 25, and 35°C, respectively. Hydrolytically stable at pH 4.
Main hydrolysis product: 5-sulphonatosiophthalic acid

Key value for chemical safety assessment

Half-life for hydrolysis:

268 d

at the temperature of:

15 °C

Additional information

The rate of hydrolysis of the test substance as a function of pH was determined (Clariant Produkte (Deutschland) GmbH (c), 2013, OECD 111). The preliminary test (5 days at 50°C) indicated less than 10% hydrolysis at pH 4.0. Therefore the test substance can be considered hydrolytically stable at pH 4.0 (t 0.5 > 1 year at 25°C). In the main test hydrolysis at pH 1.2 was determined at 37°C; hydrolysis at pH 7.0 and pH 9.0 was determined at 15°C, 25°C and 35°C. The half life at 25°C was 69 days and 1 day at pH 7 and pH 9, respectively. The main hydrolysis product was 5 -sulphonatosiophthalic acid, due to hydrolysis of the ester groups of the test substance.