Pentasodium 4-amino-6-[[5-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-2-sulphonatophenyl]azo]-3-[(2,5-disulphonatophenyl)azo]-5-hydroxynaphthalene-2,7-disulphonate

Endpoint summary

Description of key information

A GLP-compliant study was performed to measure the abiotic degradation of the read across test article according to OECD guideline 111 at 50 ± 0.1 °C at each of pH 4.0, pH 7.0, and pH 9.0. The results of pH 7.0 and pH 9.0 showed no significant degradation of FAT 45168/A. The percentage of the hydrolysis at pH 7.0 and pH 9.0 respectively was found to be less than 10 % after 5 days incubation at 50 °C ± 0.1 °C. In conclusion, FAT 45168/A was considered to be hydrolytically stable at pH 7.0 and pH 9.0. Therefore, according to the guidelines no further testing of FAT 45'168/A was performed at pH 7.0 and pH 9.0. The results at pH 4.0 showed that FAT 45168/A is not stable at this pH range. The percentage of hydrolysis at pH 4.0 was found to be more than 10 % after 5 days. Therefore, according to the guidelines advanced testing of FAT 45168/A was performed to determine the rate constant (K25) of the FAT 45168/A hydrolysis reaction at pH 4.0. As a result of all observations, it can be stated that the hydrolysis reaction of FAT 45168/A at pH 4.0 and 25 °C was estimated to be relative slow (t1/2 (25 °C) = about 100 days). The activation energy of FAT 45168/A at pH4.0 was estimated to be 60.1 kJ/mol and the reaction rate constant (K) of FAT 45168/A at pH 4.0 was estimated to be 2.9 10E-4 per hour.