Tetrasodium 3-[[4-[[4,6-bis-[(3-sulfonatoprop-1-yl)thio]-1,3,5-triazin-2-yl]amino]-2-methyl-5-methoxy-phenyl]azonaphthalene-1,5-disulfonate

Short-term toxicity to fish

Description of key information

96 hour LC50 >100 mg/L in freshwater Oncorhynchus mykiss, OECD 203, EU Method C1, Thomas 1996

Additional information

The acute toxicity potential of the test material to fish was investigated in the key study by Thomas (1996). The study was conducted under GLP conditions and in accordance with the standardised guidelines OECD 203 and EU method C1, using Oncorhynchus mykiss (Rainbow Trout) as the test organism. Based on the principles for assessing data quality defined by Klimisch et al. (1997), the study was assigned a reliability score of 1.

A preliminary limit test was conducted at nominal concentrations of 0 (dilution water control), 0.1, 1, 10 and 100 mg/L for 96 hours under static conditions. Seven fish were exposed to the water control and limit dose, while the 0.1, 1 and 10 mg/L nominal concentrations were administered to groups of five fish. Mortality, sub-lethal effects and abnormalities at each concentration was recorded at 0, 2, 4, 24, 48, 72 and 96 hours.

No mortality occurred in any dose group. No clinical signs were noted, although at 100 mg/L fish were noted to be swimming calmly close to the bottom of the aquarium. Since the test material was found not to be toxic at the nominal limit concentration of 100 mg/L, a definitive study was deemed unnecessary and samples of the control and 100 mg/L solutions were analysed to verify the concentration of the test material at 0, 24, 48, 72 and 96 hours during the test. As measured concentrations were >80 % of the nominal concentrations, all results were based on nominal values.

Under the conditions of the test, no mortality was recorded in any of the dose groups over the 96 hour observation period. The LC50 is therefore is considered to be > 100 mg/L (maximum concentration tested).