N-(3-(trimethoxysilyl)propyl)ethylenediamine

Toxicity to soil microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil microorganisms

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to other study

Additional information

In accordance with Column 2 of REACH Annex IX, there is no need to further investigate the effects of this substance in terrestrial toxicity studies because, as indicated in guidance R.7.11.6 (ECHA 2017), the quantitative chemical safety assessment (conducted according to Annex I of R EACH) indicates that the Risk Characterisation Ratio is below 1, and therefore the risk is already adequately controlled and further testing is not justifiable.

The substance is highly water soluble and is not readily biodegradable but has low bioavailability and low potential for adsorption (based on log K_ow <3 (-4) and log K_oc -0.7). Low toxicity was observed in short-term aquatic tests and the occurrence of more severe toxic effects in the terrestrial compartment that were not expressed in the aquatic studies would be considered unlikely.

Based on the aquatic data set, the most sensitive trophic level is algae. A soil hazard category 3 has been derived for the substance. According to the screening assessment for soil hazard category 3, the PNECsoil has been calculated from PNECfreshwater on the basis of the equilibrium partitioning method and a confirmatory long-term toxicity to terrestrial organisms is not thought to be necessary for chemical safety (see the terrestrial endpoint summary discussion). The risk characterisation ratio (RCR) based on PNECsoil derived from the equilibrium partitioning method is <1.

It is recognised that the aquatic PNEC used in the EQPM does not take into account any indicator for effects in aquatic microorganisms. However, the aquatic fish, invertebrate and algae data suggest that aquatic microorganisms are comparatively less sensitive: the DIN 38412-8 Pseudomonas putida growth inhibition test recorded a 16-hour EC₁₀ value of 20 mg/l (nominal, as silanol hydrolysis product) (Diefenbach, 1995, see IUCLID Section 6.1.7), while the lowest NOEC for the silanol hydrolysis product long-term data was 2.5 mg/l (Springborn Smithers, 2002). Therefore, it is unlikely that the interim PNECterrestrial based on aquatic ecotoxicity test results would not be protective for terrestrial microorganisms.

The chemical safety assessment using EQPM does not suggest any unacceptable risks for the terrestrial compartment. Therefore, it is unlikely that the PNECterrestrial derived by the equilibrium partitioning method based on the PNECaquatic would not be protective for terrestrial microorganisms. The chemical safety assessment using EQPM does not suggest any unacceptable risks for the terrestrial compartment.

Overall, it is concluded that the risk characterisation conclusion is sufficiently conservative and therefore further 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, CSR Section 7, and Chapters 9 and 10 of the Chemical Safety Report, respectively.