Registration Dossier

Diss Factsheets

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

In accordance with Column 2 of REACH Annex IX, the long-term aquatic toxicity to invertebrates study does not need to be conducted as the chemical safety assessment according to Annex I indicates that this is not necessary.
In addition, short-term aquatic studies conducted with constituents of the substance indicate that no effects at the limit of solubility are expected for the registered substance. The test media preparation is extremely difficult for this substance. This is due to the low water solubility of the substance and its potential to hydrolyse. As a consequence there is the likelihood that dissolved and undissolved phases of the parent substance will be present simultaneously potentially causing physical effects and that hydrolysis product will also be present. Preparation of a test medium containing a pre-hydrolysed form of the substance for testing is not technically achievable due to the formation of different chemical species and different phases.

Key value for chemical safety assessment

Additional information

In accordance with Column 2 of REACH Annex IX, there is no need to further investigate the effects of this substance in a long-term aquatic toxicity to invertebrates study because, as indicated in guidance R.7.8.4.3 (ECHA 2016), the quantitative chemical safety assessment (conducted according to Annex I of REACH) indicates that the Risk Characterisation Ratio is below 1, even with due consideration of contributing uncertainties, and therefore the risk is already adequately controlled and further testing is not justifiable.

A PNEC has been derived for the purpose of chemical safety assessment. An assessment factor of 1000 was applied to derive the freshwater PNEC. This high assessment factor to derive the predicted no-effect level already reflects the typically higher value of a short-term EC50 compared to a long-term EC10. For a narcotic chemical without a specific mode of toxic action, it is unlikely that the aquatic PNEC would be significantly over-estimated using this method.

In addition, due to the difficulties experienced in short-term toxicity studies, long-term toxicity studies are thought to be scientifically unjustified. The available BCF study supports this conclusion.

Overall it is concluded that the risk characterisation conclusion is sufficiently conservative in respect of any uncertainties and therefore further in vivo testing is not considered necessary.

Details on how the PNEC and the risk characterisation ratio have been derived can be found in IUCLID Section 6.0 and Chapters 9 and 10 of the Chemical Safety Report, respectively

Categories Display