Disodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)][6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]naphthalene-2-sulphonato(3-)]cobaltate(2-)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

Data is predicted using OECD QSAR toolbox version 3.3 and QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: estimated data

Principles of method if other than guideline:

Prediction was done by using OECD QSAR toolbox v3.3,

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: Disodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-)
- IUPAC name: Disodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)][6-amino-5-[(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-)
- Molecular formula: C33H22CoN9O11S2. 2 Na
- Molecular weight: 890 g/mole
- Smiles :Cc1cc(N(=O)=O)c2c(c1)N=N1c3c4ccc(S(O)(=O)=O)cc4ccc3N[Co]{2+}113(Nc4ccc5cc(S(=O)(=O)N C)ccc5c4N1=Nc1ccc(N(=O)=O) cc1O{-}.3).O{-}2Na
- Substance type: Organic
- Physical state: Solid

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

15.149 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mobility

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

(((((("a" or "b" )  and ("c" and ( not "d") )  )  and "e" )  and ("f" and ( not "g") )  )  and ("h" and ( not "i") )  )  and ("j" and "k" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Radical OR Radical >> Radical mechanism via ROS formation (indirect) OR Radical >> Radical mechanism via ROS formation (indirect) >> Diazenes OR Radical >> Radical mechanism via ROS formation (indirect) >> Nitro Azoarenes OR SN1 OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation OR SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitro Azoarenes by DNA binding by OASIS v.1.3 ONLY

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as SN1 OR SN1 >> Nitrenium Ion formation OR SN1 >> Nitrenium Ion formation >> Aromatic azo OR SN1 >> Nitrenium Ion formation >> Aromatic nitro by DNA binding by OECD ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Non binder, MW>500 by Estrogen Receptor Binding

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Non binder, impaired OH or NH2 group OR Non binder, without OH or NH2 group OR Strong binder, OH group OR Very strong binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Class 5 (Not possible to classify according to these rules) by Acute aquatic toxicity classification by Verhaar (Modified) ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Not classified by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Acrylamides OR Amides by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Not classified by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Imides OR Not Related to an Existing ECOSAR Class by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 839 Da

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 913 Da

Validity criteria fulfilled:

not specified

Conclusions:

The EC50 was estimated to be 15.14 mg/l when Daphnia magna was exposed with Disodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-)

Executive summary:

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the short term aquatic toxicity to invertebrates was estimated for Disodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-). The EC50 was estimated to be 15.14 mg/l when Daphnia magna was exposed with Disodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-).

On the basis of the effect concentration the test chemical is considered toxic and can be classified in the category "Aquatic chronic 3" as per CLP classification.

Description of key information

Short-term toxicity to aquatic invertebrates:

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the short term aquatic toxicity to invertebrates was estimated forDisodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-). The EC50 was estimated to be 15.14 mg/l when Daphnia magna was exposed withDisodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-).

On the basis of the effect concentration the test chemical is considered toxic and can be classified in the category "Aquatic chronic 3" as per CLP classification.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

15.14 mg/L

Additional information

Short-term toxicity to aquatic invertebrates:

In a prediction done by SSS (2018) using the OECD QSAR toolbox with log kow as the primary descriptor, the short term aquatic toxicity to invertebrates was estimated forDisodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-). The EC50 was estimated to be 15.14 mg/l when Daphnia magna was exposed withDisodium [6-amino-5-[(2-hydroxy-4-nitrophenyl)azo]-N-methylnaphthalene-2-sulphonamidato(2-)] [6-amino-5- [(2-hydroxy-4-nitrophenyl) azo]naphthalene-2-sulphonato(3-)]cobaltate(2-).

On the basis of the effect concentration the test chemical is considered toxic and can be classified in the category "Aquatic chronic 3" as per CLP classification.

The above prediction for target was suppported by experimental result for structurally similar read across substance sodium 4-[(2-hydroxy-1-naphthyl) diazenyl]benzenesulfonate (CAS: 633 -96 -5) summarized in Journal of Hazardous Materials, Vol. 276, Pg. no. 332–338, 2014.

Short term toxicity study toDaphnia similiswas carried out for 48 hrs. Neonates of less than 24 h old isolated from Daphnia culture were used for the study. Five test organisms were placed in each screw cap tubes, filled with 10 mL solution, and then incubated at 21±0.3°C in the dark. After 48 h of exposure, the number of immobile organisms was recorded. Jspear software was used to calculate the median 50% immobilization concentration (EC50). Based on immobilization of test organism by test chemical Acid Orange 7, the EC50 value was determine to be 87 mg/l along with confidence interval (p – 0.05) of 76-99 mg/l.

The above experiental data for read across substance was further supported by another experimental study for structurally similar read across substance Disodium 8-(phenylamino)-5-[[4-[(5 sulphonatonaphthyl) azo]naphthyl] azo]naphthalene sulphonate (CAS: 3071 -73 -6).

Disodium 8-(phenylamino)-5-[[4-[(5 sulphonatonaphthyl) azo]naphthyl] azo]naphthalene sulphonate was used to evaluate short term toxicity on 24 h old neonates Daphnia magna as per OECD guideline 202. Untreated ISO formulation freshwater and potassium dichromate (0.32 – 3.2 mg/L) were used as negative and positive controls respectively. The effect concentration (LC50) with Daphnia magna at 48 h was observed to be 58.22 mg/l