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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

No long-term terrestrial toxicity data are available with N-[3-(dimethoxymethylsilyl)propyl]ethylenediamine (CAS 3069-29-2).

The substance hydrolyses rapidly to form N-[3-(dihydroxymethylsilyl)propyl]ethylenediamine and methanol. No biodegradation is expected for the silanol hydrolysis product, N-[3-(dihydroxymethylsilyl)propyl]ethylenediamine.

In the context of the Integrated Testing Strategy for the terrestrial compartment (ECHA guidance Chapter R.7c, terrestrial hazard classification scheme, Table R.7.11-2) (ECHA 2017) the aquatic toxicity tests do not indicate that the substance is very toxic (EC/LC50 >1 mg/L for algae, Daphnia and fish). However, despite rapid degradation of the parent substance, the silanol hydrolysis product may persist in the environment. The substance is therefore assigned to Hazard Category 3.

In this situation, a screening approach is applied: a confirmatory long-term terrestrial test is required in addition to the equilibrium partitioning approach with an extra factor of ten.

The PEC × 10 / PNECscreen based on the equilibrium partitioning method indicates the substance will have a risk characterisation ratio (RCR) >1. The highest terrestrial RCR based on PEC x 10 / PNEC is 4.69 related to deposition from air.

ECHA guidance Chapter R.7c, Table R.7.11-2 states the following: If PEC/PNECscreen >1 or indication of risk from confirmatory long-term soil toxicity test: Conduct long-term toxicity tests according to the standard information requirements Annex X (invertebrates and plants), choose lowest value for derivation of PNECsoil.

In accordance with the ECHA guidance, because the PEC/PNECscreen is >1 and the hydrolysis product is considered persistent in soil (DT50 >180 days), long-term terrestrial invertebrate and plant tests are proposed.

Although a short-term toxicity test has been carried out with structural analogue N-(3-(trimethoxysilyl)propyl)ethylenediamine (CAS 1760-24-3), with Eisenia foetida where no effects were observed at the highest tested concentrations (>1000 mg/l) (RCC, 2004), the REACH requirements are that long-term tests are performed.

In addition, toxicity was observed in the aquatic microorganism test, read across from a structural analogue (16 hour EC50 67 mg/L; EC10 25 mg/L (Pseudomonas putida, growth rate) (Diefenbach, 1994)). ECHA guidance Chapter R.7c states “Where inhibition of sewage sludge microbial activity has been observed in Annex VIII testing, a test on soil microbial activity will additionally be necessary for a valid PNEC to be derived.” A soil microorganisms nitrogen inhibition test (OECD 216) is therefore also proposed.