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

Endpoint summary

Additional information

Short-term toxicity to fish

Key study

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.

 

Short-term toxicity to aquatic invertebrates

Key study

Immobilization of Daphnia magna exposed to the test item was investigated during a 48-hour static test. The test was performed in glass beakers of 150 mL capacity, containing 100 mL of each treatment per replicate. Eight test item concentrations: 0.8, 1.6, 3.2, 6.3, 12.5, 25, 50 and 100 mg/L plus the control were used. Daphnia magna was observed for immobilization after 24 and 48 h of exposure. The Daphnia magna was considered immobile if they showed no ability to swim within 15 seconds after agitation of the test vessel. At exposure termination in the test item concentrations of 0.8, 1.6, 3.2, 6.3, and 12.5 mg/L immobilization was 15, 45, 55, 65 and 95%, respectively. In the test item concentrations 25, 50 and 100 mg/L the immobilization was 100%. In the control the immobilization of Daphnia magna was 5%. The concentrations of the test item were determined with a validated spectrophotometric method. In the samples collected at exposure initiation the determined test item concentrations were in the range of 81.8 – 88.1% of nominal concentration. Therefore, the results confirm correct preparation of the test item concentrations. In the samples collected at exposure termination the determined test item concentrations were in the range of 80.8 – 86.2% of nominal concentration. Therefore, the test item concentrations were stable under test conditions. The following endpoint values were determined on the basis of the nominal test item concentrations after 48 h of exposure:

EC50/48 h value is 2.52 mg/L (95% confidence interval 1.75 – 3.44)

LOEC/48 h value 1.60 mg/L

NOEC/48 h value 0.80 mg/L.

 

Disregarded Study

The test substance was tested for its acute toxicity to Daphnia magna in a 48 hours static test (limit-test) according to OECD guideline 202 and EU method C.2. The daphnia were exposed to the test substance (12 mg/L) in 250 mL beakers containing 100 mL test medium with 10 animals per beaker. All tests are running in duplicate. Test evaluations were done by visual assessment of the mobility of the daphnia after 24 and 48 hours. Due to the low test substance concentration ( 12% act. ingr.) the study is considered to be disregarded and no EC50 value can be determined.

 

Toxicity to microorganisms

Key study

An activated sludge respiration inhibition test with the test item was performed according to OECD guideline 209. The purpose of the 3-hour test was to evaluate the influence of the test item on the activity of the activated sludge by measuring the respiration rate under defined conditions. The test substance was added in the required amounts to the test concentrations (62.5, 125, 250, 500 and 100 mg/L) directly to the test vessels contained deionized water. Afterwards synthetic medium was added to each test vessel. After addition of 250 mL of inoculum suspension (3 g/L dry weight) the incubation was started by aeration of the test vessels with pressured air. The consumption rate of each test concentration, the reference substance (3,5-dichlorophenol) and the blank controls were determined after 3 hours of exposure for a period of 8 – 10 min. The consumption rates were used to calculate the inhibition effects.

The EC50 of the reference substance 3,5-dichlorophenol was in the range of 2-25 mg/L in 3 hours. An EC10 = 270 mg/L, EC20 = 930 mg/L, EC50 >1000 mg/L, EC80 >1000 mg/L were found in the activated sludge respiration inhibition test with 3 hour residence time for the test substance.

 

Toxicity to aquatic plants other than algae

Key study

The growth of Lemna gibba exposed to the test item was investigated in a 7 day static test to determine the test item concentrations causing 10, 20 and 50% inhibition of growth rate (r) and yield (y). The test was performed in glass beakers containing 400 mL of each treatment per replicate. Seven test item concentrations of 0.032, 0.16, 0.8, 4.0, 20, 100 and 500 mg/L plus the control were used in the test. 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 84.3 – 95.5% 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 81.4 – 101.1% of the nominal concentration. Therefore, the test item concentrations were stable under static test conditions. The endpoint values were determined on the basis of the nominal test item concentrations. At exposure termination, in the test item concentrations of 0.032, 0.16 and 0.8 mg/L no distinctive changes from the normal development of plants in the control were observed. In the test item concentration of 4.0 mg/L fronds were slightly bent down. In the test item concentration of 20, 100 and 500 mg/L,shorter roots were observed. In the test item concentrations of 100 and 500 mg/L spots of chlorosis or necrosis on fronds were observed. Moreover, in the test item concentrations of 20 and 100 mg/L bent down fronds were observed, in the test item concentration of 500 mg/L break up of colonies was observed. The endpoint values based on nominal test item concentrations are given below:

 

Based on frond number:

ErC50/7d: is 66.414 mg/L (95% confidence limits 29.835 – 193.167)

ErC20/7d: is 0.556 mg/L (95% confidence limits 0.109 – 1.549)

ErC10/7d: is 0.046 mg/L (95% confidence limits 0.004 – 0.201)

EyC50/7d: is 1.407 mg/L (95% confidence limits 0.447 – 3.993)

EyC20/7d: is 0.043 mg/L (95% confidence limits 0.003 – 0.170)

EyC10/7d: is lower than 0.032 mg/L

 

Based on dry weight:

ErC50/7d: is 42.863 mg/L (95% confidence limits 22.347 – 93.041)

ErC20/7d: is 1.048 mg/L (95% confidence limits 0.283 – 2.462)

ErC10/7d: is 0.151 mg/L (95% confidence limits 0.022 – 0.491)

EyC50/7d: is 1.341 mg/L (95% confidence limits 0.579 – 3.017)

EyC20/7d: is 0.097 mg/L (95% confidence limits 0.015 – 0.262)

EyC10/7d: is lower than 0.032 mg/L.