Cuprate(4-), [.mu.-[[3,3'-[(1-oxido-1,2-diazenediyl)bis[[2-(hydroxy-.kappa.O)-4,1-phenylene]-2,1-diazenediyl-.kappa.N1]]bis[4-(hydroxy-.kappa.O)-2,7-naphthalenedisulfonato]](8-)]]di-, ammonium sodium

Short-term toxicity to fish

Description of key information

Based on the zebrafish mortality results of the acute toxicity test with the test item the following endpoint values were determined: 
The LC50/96 h value is 48.53 mg/L (95% confidence limits: 30.98 – 88.77 mg/L). 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

48.53 mg/L

Additional information

In a 96-hour static acute toxicity study, approximately 3.5 months old zebrafish were exposed to the test item in groups of seven animals per treatment in glass aquaria containing 4 L of a given test item concentration or the control. Five test item concentrations were used: 100, 50, 25, 12.5 and 6.25 mg/L plus the control. The concentrations of the test item were determined with a validated spectrophotometric method. Samples of each test item concentration and the control were collected at exposure initiation and at exposure termination. The test item concentrations determined in samples collected at exposure initiation were in the range of 84.40 – 86.72% of the nominal concentration. Therefore, the results confirm correct preparation of the test item concentrations. The test item concentrations determined in samples collected at exposure termination were in the range of 82.24 – 85.04% of the nominal concentration. Therefore, the test item concentrations were stable under static test conditions. Fish were observed for survival and changes in behaviour, respiration and pigmentation after 3, 6, 24, 48, 72 and 96 h of the exposure. In the control and in test item concentrations of 6.25 and 12.5 mg/L neither mortality of fish nor symptoms of intoxication were observed during exposure. In test item concentration of 25 mg/L after 24 h of exposure one fish was found dead and faulty respiratory functions for six fish were reported. After 48 h of exposure another fish was found dead and faulty respiratory functions for all survivors were observed. In test item concentration of 50 mg/L after 24 h of exposure three fish were found dead and faulty respiratory functions for four fish were reported, what remained not changed till exposure termination. In test item concentration of 100 mg/L after 3 h of exposure unbalanced swimming behavior for one fish and faulty respiratory functions for all fish were reported. After 6 h of exposure one fish was found dead and faulty respiratory functions for six fish were reported. After 24 h of exposure six fish were found dead and faulty respiratory functions for one fish were observed, what remained not changed till exposure termination.

Based on the zebrafish mortality results of the acute toxicity test with the test item the following endpoint values were determined:

The LC50/96 h value is 48.53 mg/L (95% confidence limits: 30.98 – 88.77 mg/L).

The LC100/96 h value is higher than 100 mg/L.

The LC0/96 h value is 12.5 mg/L.

The LOEC/96 h value is 25 mg/L.

The NOEC/96 h value is 12.5 mg/L.