2,2`-[6-(phenylamino)-heteromonocycle-2,4-diyl]diphenol

Short-term toxicity to fish

Description of key information

LC50 (96h) > 0.85 µg/L (mean measured)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

0.85 µg/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 a daily test medium renewal according to the EU Commission Directive 92/69/EEC, PArt C.1 (1992), and the OECD Guideline 203, (1992).
A limit test was performed to demonstrate that the test item has no toxic effect on the test fish up to the solubility limit of the test item in the test water.

The measured concentration of the test item in the test medium was 1.2 µg/L at the start of the test medium renewal periods. During the test medium renewal periods, the test item concentration slightly decreased to the range of 0.74 and 0.48 µg/L. The mean measured test item concentration during the test medium renewal periods was in the range of 0.95 and 0.75 µg/L (calculated as geometric mean of the concentration measured at the start and the end of the renewal periods). From these values, the mean measured test item concentration during the test period of 96 hours was calculated as arithmetric mean to be 0.85 µg/L.
The biological results were related to the loading rate of 100 mg/L (mean measured 0.85 µg/L).
In the control and at the loading rate of the test item of 100 mg/L, no mortality or other visible abnormalities were determined during the test period of 96 hours.

Thus, the 96-hour NOEC (highest concentration tested without toxic effects after the exposure period of 96 hours) and the 96-hour LC0 of test item to zebra fish were determined to be at the loading rate of at least 100 mg/L. The 96-hour NOEC and the 96-hour LC0 might even be higher but loading rates higher than 100 mg/L and concentrations of the test item above the solubility limit of the test item in the test water were not tested in accordance with the test guidelines. 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. These values could not be quantified due to the absence of toxicity of test material at the highest concentration which could be dissolved in the test water at the loading rate of 100 mg/L.

In conclusion, the test item had no acute toxic effects on the test fish up to its solubility limit in test water under the present conditions of the test.