2,4,6,8-tetramethyl-1,3,5,7-tetraoxacyclooctane

Endpoint summary

Description of key information

Acute toxicity to Daphnia Magna:

The acute toxicity of the test item to Daphnia magna was determined in a 48-hour static test according to the EU test method C.2. A limit test was performed in accordance with the test guidelines to demonstrate that the test item has no toxic effect on the test organisms up to and including a nominal concentration of 100 mg/L. Thus, the only nominal concentration tested was 100 mglL. The measured concentration of the test item in the test medium was 107 and 103 mg/L at the start and end of the test, respectively. Thus, the test item was stable in the test medium over the test period of 48 hours. The biological results were therefore related to the nominal concentration of the test item. The preparation of the test medium was based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000. In the control and at the nominal test concentration of 100 mg/L no immobilized daphnids were determined during the test period of 48 hours. Therefore, the 24h- and 48h-EC50 was found to be > 100 mg/l, the NOEC at 24h and 48h was 100 mg/l.

Algal growth inhibition:

The acute toxicity of the test item to green algae (Desmodesmus subspicatus) was determined in a 72 -hour static test according to the OECD test method no. 201. A full test with five test item concentrations (200, 100, 50, 25 and 12.5 mg/L) was performed in accordance with the test guidelines. The mean total recovery for all measured test solutions was 99.3% of the nominal concentration. Therefore a correction of the biological results based on measured concentrations was not performed. After an exposure period of 72 hours, the EC50 for growth rate and yield was determined to be higher than 200 mg test item/L.