Reaction mass of Cobalt, 4-[4-[[4-[[[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1Hpyrazol-4-yl)azo]-4-hydroxyphenyl]sulfonyl]amino]phenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonate 4-[4-[[4-[[[3-[[4,5-dihydro-3-methyl-5-oxo-1-(4-sulfophenyl)-1H-pyrazol-4-yl]azo]-4-hydroxyphenyl]sulfonyl]amino]phenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1Hpyrazol-1-yl]benzenesulfonate sodium complexes and Cobaltate(3-), bis[4-[4-[[4-[[[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-4-hydroxyphenyl]sulfonyl]amino]phenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1Hpyrazol-1-yl]benzenesulfonato(3-)]-, trisodium and Cobaltate(5-), bis[4-[4-[[4-[[[3-[[4,5-dihydro-3-methyl-5-oxo-1-(4-sulfophenyl)-1H-pyrazol-4-yl]azo]-4-hydroxyphenyl]sulfonyl]amino]phenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1Hpyrazol-1-yl]benzenesulfonato(4-)]-, pentasodium

Endpoint summary

Description of key information

Short-term toxicity to aquatic invertebrates:

EC₅₀ (48 h, Daphnia magna) = 38.33 mg/l (based on nominal concentrations of test item)

Toxicity to aquatic plants other than algae:

E_rC₅₀ (7d, Lemna minor) = 121.7 and 164.5 mg/l, based on frond number and dry mass, respectively (based on nominal concentrations of test item)

Short-term toxicity to fish:

LC₅₀ (48 h,Oncorhynchus mykiss) = 120 mg/l (based on nominal concentrations of test item)

Toxicity to microorganisms:

IC₅₀ > 100 mg/l

Additional information

Firstly, it is worth saying that the substance is very water soluble (i.e. > 10 g/l); it has a log K_ow value lower than 4 (indicating a low potential for bioaccumulation) and is not rapidly degradable.

Short-term toxicity to aquatic invertebrates

The acute toxicity of the test item to Daphnia magna was evaluated in an experimental study according to the OECD Guideline 202 (2004) and the EU Method C.2 of the Regulation EC 440/2008. The study was performed using 5 concentrations ranging from 4.6 to 100 mg/l. For each test concentration, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the number of immobilised Daphnia were counted.

Three concentrations showed toxicity with between 5 and 90% immobilisation. One of the animals was immobilised in the blank control. Potassium dichromate K₂Cr₂O₇ was used as positive control in a current reference study to assure that the test conditions are reliable. At the beginning and at the end of the test, the concentration of the test item in the test solutions was determined using a photometer method. The measured concentrations were between 103 % and 105 % of the nominal concentration at the start and after 48 hours between 95 % and 111 %. Therefore, the determination of the biological results was based on the nominal concentrations. The EC₅₀ value of the test item when exposed to Daphnia magna for 48 hours was calculated to be 38.33 mg/l.

Toxicity to aquatic plants other than algae

The acute toxicity of the test item to aquatic plants was investigated in a 7–day static test toLemna minor, according to the OECD Guideline 221 (2006). The study was performed using 5 concentrations ranging from 4.6 to 100 mg/L. The frond number and the dry mass of each replicate were determined during the experiment. Growth rate µ and the yield were determined from the frond number and the dry mass at the respective observation times. The measured concentrations lay between 85 % and 106 %, at the beginning, 103 and 120 %, at the end, of the nominal concentrations. Thus, the determination of the results was based on the nominal concentrations. All the validity criteria were met.

The 7-day E_rC₅₀vaue, based on frond number and dry mass, were found to be 121.7 mg/l and 164.5 mg/l, respectively.

Two summaries of old tests are available in which the short-term toxicity to fish and the toxicity to microorganisms were evaluated respectively. Due to insufficient documentation for assessment, the reliability of the data cannot be judged.

The short-term toxicity to fish was investigated to the rainbow trout, according to an internal method. Starting from a nominal concentration of 20 mg/l, differential concentrations were tested during a study period of 48 h. The LC₅₀ after 48 hours was indicated to be 120 mg/l (nominal).

The toxicity to microorganisms (activated domestic water sludge) was investigated in a respiration rate test (ETAD Method Nr. 103). The IC₅₀ was reported to be greater than 100 mg/l.

 

Justification for classification or non-classification

According to the CLP Regulation (EC) n. 1272/2008, Part 4: Environmental Hazards, the substances can be classified for hazardous to the aquatic environment when the following criteria are met:

A )Acute (short-term) aquatic hazard Category Acute 1: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC 50 (for algae or other aquatic plants) ≤ 1 mg/l.

B) Long-term aquatic hazard (iii) Substances for which adequate chronic toxicity data are not available and the substance is not rapidly degradable and/or the experimentally determined BCF ≥ 500 (or, if absent, the log K ow ≥ 4).

-Category Chronic 1: 96 hour LC₅₀ (fish) and/or 48 hour EC₅₀ (crustacea) and/or 72 or 96 hour E_rC₅₀ (for algae or other aquatic plants) ≤ 1 mg/l;

-Category Chronic 2: 96 hour LC₅₀ (fish) and/or 48 hour EC₅₀ (crustacea) and/or 72 or 96 hour E_rC₅₀ (for algae or other aquatic plants) > 1 to ≤ 10 mg/l;

-Category Chronic 3: 96 hour LC₅₀ (fish) and/or 48 hour EC₅₀ (crustacea) and/or 72 or 96 hour E_rC₅₀ (for algae or other aquatic plants) > 10 to ≤ 100 mg/l.

The test item is not rapidly degradable and the available acute toxicity test on Daphnia magna fixed the effect level that meets the criteria related to the hazard Category Chronic 3 (> 10 to ≤ 100 mg/l). Therefore, the test item is classified as Aquatic Chronic 3 according to the CLP Regulation (EC) no. 1272/2008.