Reaction mass of 2,6-bis(1-phenylethyl)phenol and 2,4,6-tris(1-phenylethyl)phenol

Short-term toxicity to aquatic invertebrates

Description of key information

48h EC50 >= saturated solution

Additional information

One key study is available for this endpoint (LAMY, 1997). In this study, the test item composition is 80% Tristyrenated phenol and 20% Distyrenated phenol (weight basis). The acute toxicity of the test substance to Daphnia magna was determined in a 48 hour static test according to the OECD Guideline No. 202 (1984) and GLP. Due to very low solubility of the test substance, two saturated solutions at 30 and 100 mg/L in test medium have been prepared by stirring for 48 hours in the dark at 20°C, 2 hours of settling and vacuum filtration using glass microfiber, previoulsy washed with deionised water.The resulting solutions were clear and uncoloured. They were considered as "saturated solutions" from which the range test concentrations of 20, 40, 60, 80 and 100 % of saturated concentrations were prepared. No analytical measurement of the tested concentrations has been performed.

15% and 5% of immobilisation have been observed for the 100% saturated solutions at 100 mg/L and 30 mg/L respectively after 48h of exposure. No immobilisation has been observed at the other test solutions and in the controls. The 48hEC50 of the test item was found to be higher than a saturated concentration. Based on this result, the test item (80% TSP and 20%DSP) is considered as not dangerous to the aquatic organisms tested.

As no analytical monitoring has been performed, the concentration tested can not be checked. Therefore, this study is considered as reliable with restrictions.