Chromate(2-), [2,4-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)][3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulfonato(3-)]-, disodium

Endpoint summary

Description of key information

FAT 20010 was found to be very toxic to aquatic species.

Additional information

Short term toxicity tests are available for all the three tropic levels (fish, invertebrates and aquatic plants). In an 96 h acute fish toxicity test, the test substance FAT 20010 was observed to have 96 h LC50 to Zebra fish <1.0 mg/L. 48 h EC50 value of FAT 20010/C to Daphnia magna was calculated to be 31 mg/L. The NOEC and EC0 value after 48 hours was determined to be 7.9 mg/I. The test material FAT 20010 is a dark color dye which when mixed in test medium will impart dark color. Due to light absorption, colored substances such as dyes can inhibit algal growth, which is not the result of a toxic action. This shading effect can confound measures of chemical toxicity and thus impair the risk assessment. In an effort to avoid this problem Lemna gibba (Duckweed) Growth Inhibition test (Static) is conducted. In a GLP-compliant OECD 221 guideline study Lemna gibba (Duckweed) exposed to the test item FAT 20010/E recorded: 7 day ErC50 based upon the frond number is 8.03 mg/L (8.93 - 7.23 mg/L). 7 day EyC50 based upon the frond numbers is 1.33 mg/L (1.45 - 1.22 mg/L). 7 day ErC50 based upon the frond dry weight is 8.15 mg/L (9.33 - 7.12 mg/L). 7 day EyC50 based upon the frond dry weight is 0.72 mg/L (0.79 - 0.66 mg/L). Based on these results the test substance FAT 20010 can be regarded as very toxic to aquatic species.