p-[4,5-dihydro-4-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonic acid, sodium salt

Endpoint summary

Additional information

The substance is expected to hydrolyse under normal environmental conditions. Experimental studies on hydrolytic effects demonstrated that the substance does undergo hydrolysis at environmentally relevant pH’s, with a half life of 6.75 days at pH 7 (20°C). As such, degradation is anticipated via this route. Studies on direct phototransformation in water are not available but it is assumed on the basis of chemical structure and nature of use that the substance is not degraded by direct photolysis. It is concluded, therefore, that abiotic processes would contribute significantly to the depletion of the substance within the environment.

Due to the effects of hydrolysis at environmentally relevant pH’s, it is proposed that the substance cannot be considered to have a half life in marine water higher than 60 days, despite the limited ability to biodegrade. Based on its high water solubility, low partition coefficient and moderate to rapid hydrolysis rate at environmentally relevant pH’s, it can be concluded that it is unlikely that Reactive Yellow 15 could potentially be persistent within the environment.

Abiotic effects will result in eventual removal from the environment and hence significant contact with the organisms in the food chain can be considered to be minimised.

Reactive Yellow 15 has a measured log Pow of <-5.8. This value indicates that possible bioaccumulation in the food chain is not anticipated. No direct information on bioaccumulation is available. Given the fact that the substance is subject to significant hydrolysis at biologically relevant pH’s (7 and 9), it is anticipated that bioaccumulation of the substance itself would not occur, as hydrolytic effects in association with metabolic effects would result in removal of the substance.