3-Pyridinecarbonitrile, 4-methyl-2,6-bis[(4-methylphenyl)amino]-5-[2-[2-(trifluoromethyl)phenyl]diazenyl]-

Short-term toxicity to fish

Description of key information

The 96-hour NOEC and the 96-hour LC0 of test item to zebra fish were determined to be at least the loading rate of 100 mg/L or at least at the solubility limit of the test item. The 96-hour LOEC, the 96-hour LC50, and the 96-hour LC100 were clearly higher than the loading rate of 100 mg/L or above the water solubility limit of the test item. Hence, the test substance is with high probability acutely not harmful to fish. No toxic effects occur within the range of water solubility.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

The acute toxicity of the test item to zebra fish (Brachydanio rerio) was determined in a 96-hour semi-static test with daily test medium renewal according to the EU Commission Directive 92/69/EEC, Part C.1 (1992), and the OECD Guideline for Testing of Chemicals No. 203, (1992) (RCC Ltd. 2004). A limit test was performed according to the test guidelines to demonstrate that the test item has no toxic effect on the test organisms up to the solubility limit of the test item in test water. Additionally, a control was tested in parallel. Before the start of the test and prior to each test medium renewal, the test medium was prepared as follows: A supersaturated dispersion of the test item with a loading rate of 100 mg/L was continuously stirred at room temperature in the dark over 96 hours. Then, the dispersion was filtered (0.45 µm membrane filter). The undiluted filtrate with the maximum concentration of dissolved test item was used as single test concentration. The test medium was prepared just before the start of the test or just prior to each test medium renewal. In the test medium samples from the start and the end of the test medium renewal periods of 24 hours, the measured test item concentration was below the limit of detection (LOD) of approximately 0.007 µg/L. Therefore, the biological results are based on the loading rate of the filtrate of 100 mg/L. In the control and in the undiluted filtrate with the loading rate of 100 mg/L containing the highest test item concentration which could be dissolved in the test water, all fish survived until the end of the test and no visible abnormalities were observed in the test fish. Therefore, the 96-hour NOEC (highest concentration tested without toxic effects after the exposure period of 96 hours) and the 96-hour LCO of the test item to zebra fish were determined to be at least the loading rate of 100 mg/L or at least at the solubility limit of the test item. The 96-hour NOEC and the 96-hour LC0 might even be higher than this concentration but higher test item concentrations could not be tested due to its low water solubility. The 96-hour LOEC (lowest concentration with toxic effects), the 96-hour LC50, and the 96-hour LC100 were clearly higher than the loading rate of 100 mg/L or above the water solubility limit of the test item. These values could not be quantified due to the absence of toxicity of test itemat the highest concentration which could be dissolved in the test water.