A mixture of: trisodium (2,4(or 2,6 or 4,6)-bis(3,5-dinitro-2-oxidophenylazo)-5-hydroxyphenolato)(2(or 4 or 6)-(3,5-dinitro-2-oxidophenylazo)-5-hydroxy-4(or 2 or 6)-(4-(4-nitro-2-sulfonatoanilino)phenylazo)phenolato)ferrate(1-); trisodium bis(2,4(or 2,6 or 4,6)-bis(3,5-dinitro-2-oxidophenylazo)-5-hydroxyphenolato)ferrate(1-); trisodium (2,4(or 2,6 or 4,6)-bis(3,5-dinitro-2-oxidophenylazo)-5-hydroxyphenolato)(2(or 4 or 6)-(3,5-dinitro-2-oxidophenylazo)-5-hydroxy-4(or 2 or 6)-(4-nitro-2-sulfonatophenylazo)phenolato)ferrate(1-); trisodium (2,4(or 2,6 or 4,6)-bis(3,5-dinitro-2-oxidophenylazo)-5-hydroxyphenolato)(2(or 4 or 6)-(3,5-dinitro-2-oxidophenylazo)-5-hydroxy-4(or 2 or 6)-(3-sulfonatophenylazo)phenolato)ferrate(1-); disodium 3,3'-(2,4-dihydroxy-1,3(or 1,5 or 3,5)-phenylenediazo)dibenzenesulfonate

Short-term toxicity to aquatic invertebrates

Description of key information

EC50 (48 h, Daphnia magna) 48 mg/L (geom. mean of measured conc.)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

48 mg/L

Additional information

An experimental study for short-term toxicity to Daphnia magna is available on the substance. Daphnia magna were exposed for 24 hours to a concentration range of 100 to 1000 mg/L forming a geometric progression with a factor of 1.8 according to OECD Guideline 202 (1984) and the EU method C.2 of Directive 84/449. The test was performed in duplicate with 10 daphnia per vessel.

After 24 hours of exposure the total rate of immobilisation of daphnia was 95 % at 1000 mg/L, 70 % at 560 mg/L. 40 % at 320 mg/L, 30 % at 180 mg/L and 15 % at 100 mg/L.

The EC50 (24 h, Daphnia magna) was calculated to be nominally 313 mg/L with 95 % confidence interval ranging from 236 to 415 mg/L (slope = 2.43).

As the experimental phase was only for 24 h, a weight of evidence approach is followed. Specifically, data from Similar Substance 01 is used in order to complete the assessment of aquatic short-term toxicity to Daphnia magna up to 48 hours of exposure following a read-across approach. Justification for read-across is detailed in attachment to this summary.

A static test was performed using Similar Substance 01 according to the OECD Guideline 202 (2004) and the EU method C.2 of the Regulation (EC) 440/2008. 5 concentrations were used ranging from 4.6 to 100 mg/L (nominal concentration). For each test concentration and the blank control, 20 Daphnia were exposed to the test item for 48 hours. After 24 and 48 hours, the immobilised Daphnia were counted. Potassium dichromate K₂Cr₂O₇ was used as positive controlin a current reference study to assure that the test conditions are reliable. At the beginning and at the end of the test, the content of the test item in the test solutions was determined using photometer-determination. The concentrations determined at the start of the test were between 45 and 81 % of the nominal concentration. At the end of the test the determined concentrations were between 94 and 108 % of the nominal concentration. Therefore, the determination of the biological results was based on geometric mean of measured concentrations. All validity criteria were met.