Aspartic acid, N-[3-(trimethoxysilyl)propyl]-, 1,4-diethyl ester

Toxicity to microorganisms

Description of key information

The substance showed 0 % respiration inhibition (mean of three replicates) of activated sludge at a test item concentration of 100 mg/L. A 3h-EC50 of higher than 100 mg/L was determined. Test concentrations are given as nominal concentrations and have not been confirmed by analytical methods (Spoo-Kloeppel, 2015).

Key value for chemical safety assessment

EC50 for microorganisms:

100 mg/L

Additional information

"Should read: > 100 mg/L"

In order to test the toxicity to microorganism of the substance, activated sludge from domestic sewage plant was exposed at a limit test item of 100 mg/L. The study was conducted in accordance with OECD Guideline 209 ‘Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation)’ (adopted: 22 July 2010) and considered the Question-and-Answer Document by the German Federal Environment Agency (Version 2012-03-02). Six controls without the test item were included in the test design, three at the start and the others at the end of the test series. A limit test was performed with 3 replicates with a test item concentration of 100 mg/L. Each batch of activated sludge was checked using 5 concentrations in the range of 2.5–40 mg/L of 3,5-Dichlorophenol as a reference compound. The oxygen uptake rates of two controls in the presence of N-allylthiourea and one replicate of 100 mg/L test item concentration in the presence of N-allylthiourea were measured after the exposure period. As no oxygen consumption was observed no differences between the heterotrophic and the nitrification oxygen uptake rates have to be calculated. After 3 hours an EC50 of higher than 100 mg/L was determined. Test concentrations are given as nominal concentrations and have not been confirmed by analytical methods.