Cobaltate(3-), bis[6-amino-5-[(2-hydroxy-3,5-dinitrophenyl)azo]-1-naphthalenesulfonato(3-)]-, sodium

Short-term toxicity to aquatic invertebrates

Description of key information

EC50 (48h) > 100 mg/l

Additional information

No data on Acid Green 104 was available, thus a read-across approach was adopted. In particular, available data on Similar Substance 01 and Similar Substance 02, i.e. cobalt complexes with 2 phenyl-azo-naphtyl ligands functionalised by similar groups, were used. A detailed description of the read-across approach is attached in section 13.

As for Similar Substance 01, the short-term toxicity towards aquatic invertebrates was assessed in 2 acute toxicity studies with Daphnia magna according to OECD guideline 202.

As the first study (2015) was not GLP compliant, a second study (2017) was conducted with the same batch of test substance. 

In both studies, nominal test solutions of 0, 6.25, 12.5, 25, 50, and 100 mg/l were used. The colour of the test solutions increased from very light pale pink to a deep purple color. In the first study, test solution colour remained unchanged throughout the test, however at test completion, reddish grains were observed at the bottom of the test vessels in the 12.5 mg/l test solution, and dark red/purple precipitate was observed in the 50 mg/l and 100 mg/l test vessels. In the second study, suspended particles of test item were visible in the 50 mg/l and 100 mg/l test concentrations from the start of the test. Throughout the test the color of test solutions remained consistent. The mean measured concentrations were 5, 10.1, 18.8, 35.3, and 66.9 in the first study and 5.0, 9.6, 18.3, 34.1, and 52.9 mg/l in the second study.

As undissolved material was present in both studies, it can be concluded that the daphnids in the test solutions were exposed to the highest achievable concentration (nominal 100 mg/l; measured 66.9 mg/l and 52.9 mg/l, respectively). Neither study revealed effects in any of the concentration groups, not even in the highest one (nominal 100 mg/l) which displayed precipitated test material.

In conclusion, up to the solubility limit no effects were noted.

As for Similar Substance 02, it was tested according to OECD guideline 202 under static exposure conditions with Daphnia magna. Nominal concentrations of 0, 45, 100 and 220 mg/l were used, corresponding to actual mean concentrations of 0, 17, 58 and 131 mg/l. In the nominal concentrations of 100 and 220 mg/l, a sediment at the bottom of the test vessel was noted after 24 h.

No effects in terms of immobilisation or abnormal behaviour were noted in controls and test concentrations. Therefore, the EC0 value after 48 h was determined to be 131 mg/l, the EC50 and EC100 values were higher than 131 mg/l.