Sodium 4-[(9,10-dihydro-4-hydroxy-9,10-dioxo-1-anthryl)amino]toluene-3-sulphonate

Short-term toxicity to aquatic invertebrates

Description of key information

The purpose of this test was to evaluate the effect of the test item on the mobility of young daphnids of the species Daphnia magna, according to the OECD 202 guideline and GLP. 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 a measured concentration of dissolved test item of at least 100 mg/L. In a pre-experiment (non GLP) it was shown, that a test item suspension with a loading rate of 250 mg/L resulted in a concentration of approximately 150 mg/L of dissolved test item in the filtrate of the suspension. Thus, a single loading rate of 250 mg/L was tested. Additionally, a control was tested in parallel (test water without addition of the test item). In this semi static test, the test medium was freshly prepared at the start of the test and at the test medium renewal after 24 hours by mixing the test item into test water at a loading rate of 250 mg/L. Intensive stirring for 1 hour was applied to reach a maximum concentration of dissolved test item in test water. After stirring, the suspension was filtered through a 0.45 μm membrane filter. The undiluted filtrate was used as test medium.

The measured concentration of the test item in the test medium with a loading rate of 250 mg/L was 127 and 141 mg/L at the start of the two renewal periods. At the end of the renewal periods, 96 and 100 % of the initially measured concentrations were found. Thus, the test item was stable during the renewal periods of 24 hours. The mean measured concentration during the test period of 48 hours was calculated to be 133 mg/L (arithmetic mean of all measurements at the start and the end of the two renewal periods). The biological results were related to the mean measured test item concentration of 133 mg/L. All the validity criteria of the OECD 202 guideline were fulfilled.

In conclusion, the test item had no acute toxic effects on Daphnia magna in a 48-hour semi-static test up to the analytically measured concentration of 133 mg/L. This concentration is even higher than the maximum concentration of 100 mg/L to be tested in a limit-test according to the test guideline.