Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Target compound titanium oxide sulphate will reach sediment compartments as they are being transformed in water immediately via hydrolysis to non-poisonous titanium dioxide and sulphuric acid. Effects may occur due to pH drop caused by the dissociation of sulphuric acid, however these effects are not considered as substance specific. Accordingly the risk assessment can be based on the assessment of the other final hydrolysis product titanium dioxide by using the Equilibrium Partitioning Method (EPM) and no testing is required.

The final hydrolysis product, titanium dioxide is released isomolar to parent compound titanium oxide sulphate. Exposure of the terrestrial compartments via air is unlikely due to its fugacity properties but may occur via dust. Even in the unlikely case that relevant amounts of titanium oxide sulphate would enter soils, the pore water contact would immediately induce the hydrolysis reaction. Titanium dioxide is considered inert and non-poisonous in the relevant isomolar levels. This is in accordance with read across from experimental data on titanium dioxide effects to terrestrial plants, micro-organisms, earthworms, and arthropods.

The risk can be assessed on the basis of isomolar titanium dioxide effects according to the Equilibrium Partitioning Method (EPM). As no aquatic toxicity is known and no threshold levels exist, the EPM predicts no toxicity to soil organisms.

In conclusion it is assessed that target compound titanium oxide sulphate nor its hydrolysis products exhibit acute or chronic toxicity to terrestrial organisms. As no effect level was reached, no threshold concentration was derived and no starting point for the calculation of soil PNECs is given.

As neither the parent compound titanium oxide sulphate nor the final hydrolysis transformation products titanium dioxide and sulphuric acid (in its neutralised form) pose a risk to terrestrial life, no further testing is required.