Alkane-alpha,omega-diyl bis{[(triethoxysilyl)propyl]carbamate}_E2

Short-term toxicity to aquatic invertebrates

Description of key information

In the acute immobilisation test withDaphnia magna(STRAUS), the effects of a Water Accommodated Fraction (WAF) with a nominal loading of 100 mg/L of the test item was determined according to OECD 202 (2004), which isequivalent to the Council Regulation (EC) No.440/2008 Method C.2 (2008). The limit test was conducted under static conditions.

The test item is a clear and colourless liquid which hydrolyses in water. In view of the difficulties associated with the evaluation of aquatic toxicity of poorly water soluble test items, a modification of the standard method for the preparation of aqueous media was performed. An approach endorsed by several important regulatory authorities in the EU and elsewhere (ECETOC 1996 and OECD 2000), is to expose the organisms to a Water Accommodated Fraction (WAF) of the test item in cases where the test item is a complex mixture and is poorly soluble in water and in the permitted solvents.

Using this approach, the aqueous medium was prepared by shaking the test item with dilution water at20 rpmfor 24 hoursat room temperatureto ensure equilibration between the test item and the water phase. 100 mgof the test item were weighed out onto a plastic slide and inserted into a PE-bottle filled with 1000 mL of dilution water (ISO test water, acc. to OECD202, Annex 3).After completion of shaking and following a 1-hour settlement period, the test item phase was separated by siphon from the approximate center of the PE-bottle to give the WAFwith a nominal loading of 100 mg/L.The WAF was slightly turbid throughout the exposure period.

Twenty daphnids were exposed to the WAF and the control.

The WAF of the test item and the control were analytically verified via analysis of the dissolved organic carbon (DOC, according to DIN EN 1484), measured as NPOC (Non Purgeable Organic Carbon) at the start of the exposure (0 hours) and at the end of the exposure(48 hours).
The measured DOC concentration was 4.09 mg C/L at the start of the exposure (0 hours) and 10.8 mg C/L at the end of the exposure (48 hours).

Per definition of the WAF, all terms related to concentrations have to be given as loading levels because partly dissolved compounds and mixtures cannot be related to concentrations. Therefore, the effect values werebased on the nominal loading level of 100 mg/L of the test item.

The water quality parameters (i.e. pH-value and dissolved oxygen concentration), measured at the start (0 hours) and at the end of the exposure (48 hours), were within the acceptable limits. The validity criteria of the test guideline were fulfilled.

 

Conclusions

At the Water Accommodated Fraction with a nominal loading of 100 mg/L of the test item no effects were observed onDaphnia magna.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L