Registration Dossier

Diss Factsheets

Ecotoxicological information

Long-term toxicity to fish

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Additional information

Due to the very rapid hydrolysis half-life of the registration substance, chemical safety assessment is based on the properties of the hydrolysis products N-[3-(dihydroxymethylsilyl)propyl]ethylenediamine and methanol. The considerations below relate to the silanol hydrolysis product N-[3-(dihydroxymethylsilyl)propyl]ethylenediamine.

Testing for long-term toxicity to fish is not considered necessary because:

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 fish study because, as indicated in guidance R. (ECHA 2016), the quantitative chemical safety assessment (conducted according to Annex I of REACH) indicates that further testing is not justified for the following reasons:  

A PNEC has been derived for the purpose of chemical safety assessment and the risk characterisation ratios are below 1.

N-[3-(Dihydroxymethylsilyl)propyl]ethylenediamine is highly water-soluble, has low bioavailability based on log Kow <3 (-4 at pH 7, corrected for ionisation), especially in pH neutral conditions, and evidence from data available within the analogue group of amine substances suggests that fish are the least sensitive trophic level.

The substance or the structural analogue N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3), have short-term data available for three trophic levels, as well as long-term invertebrate toxicity data. Based on this available aquatic data the most sensitive trophic level is algae, for which the EC50 is approximately one hundred fold lower than the LC50 for fish. Furthermore, effects observed in the short-term toxicity to fish test occurred when the substance was tested at high concentrations, well above 100 mg/l.

Overall it is concluded that the risk is adequately assessed using the short-term data and the long-term invertebrate test, and that in vivo testing on vertebrate animals is not considered necessary or justified on ethical grounds. Details on how the PNEC and the risk characterisation ratio have been derived can be found in IUCLID Section 6.0, CSR Section 7, and Chapters 9 and 10 of the Chemical Safety Report, respectively.