1,2-dihydro-6-hydroxy-1,4-dimethyl-2-oxo-5-[[3-[(phenylsulphonyl)oxy]phenyl]azo]nicotinonitrile

Endpoint summary

Description of key information

The solubility of the substance is below <1 µg/L. The substance was difficult to get into solution even at 1 µg/L under testing conditions. Hence, based on the poor solubility of the substance testing was not feasible. Due to low water solubility of the test substance (<0.7 μg/L), conducting the fish, algae, aquatic plants study was considered as not feasible. However, an 48 hr test is available conducted on Daphnia magna. Additionally, a study with toxicity to microbes is also available. The acute toxicity of the test substance toaquatic invertebrates was investigated in a study conducted according to OECD Guideline 202. Three groups each containing 10 daphnids were exposed to the test concentrations of 0, 10 and 100 mg/L for 48 hours and observed for immobilisation. The observations were recorded at 24 and 48 hours during the exposure. Only one daphnid was found to be immobilised at the concentration of 100 mg/L, while no immobilisation was reported at 0 and 100 mg/L concentrations. Hence, based on the observations the EC50 of the test substance was determined to be >100 mg/L. The toxicity of the test substance to bacteria was investigated in a study conducted according to OECD Guideline 209. The bacterial populations were exposed to test concentrations of 25.6, 64, 160, 400 and 1000 mg/L for 3 hours and observed for inhibition. 0.00, 0.00, 3.89, 0.00 and 1.62 % inhibition was recorded for concentrations 25.6, 64, 160, 400 and 1000 mg/L, respectively. Based on the findings of the study, the IC50 (3 h) was determined to be >1000 mg/L. Hence, based on the available data from invertebrate and microorganism tests the test substance Disperse Yellow 114 can be considered as not toxic to aquatic species.