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-)

Endpoint summary

Description of key information

Skin Irritation:

The dermal irritation potential of 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-) was estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

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-) was estimated to be not irritating to the skin of New Zealand White rabbits.

Based on the estimated results, 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-) can be considered to be not irritating to skin and can be classified under the category “Not Classified” as per CLP regulation.

Eye Irritation:

The ocular irritation potential of 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-) was estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

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-) was estimated to be not irritating to the eyes of New Zealand White rabbits.

Based on the estimated results, 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-) can be considered to be not irritating to eyes and can be classified under the category “Not Classified” as per CLP regulation.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

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 from OECD QSAR toolbox v3.3 and the QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done 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

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

no data available

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

not specified

Controls:

not specified

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3

Details on study design:

no data available

Other effects / acceptance of results:

no data available

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

72 h

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No signs of irritation observed

Estimation method: Takes mode value from the 6 nearest neighbours
Domain  logical expression:Result: In Domain

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

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 SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Aromatic azo AND SN1 >> Nitrenium Ion formation >> Aromatic nitro by DNA binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Michael addition OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Arenes OR SN1 >> Nitrenium Ion formation >> Tertiary aromatic amine by DNA binding by OECD

Domain logical expression index: "e"

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

Domain logical expression index: "f"

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

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OECD

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates OR SN2 OR SN2 >> SN2 reaction at sp3 carbon atom OR SN2 >> SN2 reaction at sp3 carbon atom >> Alkyl diazo OR SNAr OR SNAr >> Nucleophilic aromatic substitution OR SNAr >> Nucleophilic aromatic substitution >> Halo-triazines by Protein binding by OECD

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Alkali Earth AND Non-Metals AND Transition Metals by Groups of elements

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Halogens by Groups of elements

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 843 Da

Domain logical expression index: "l"

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

Interpretation of results:

other: not irritating

Conclusions:

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-) was estimated to be not irritating to the skin of New Zealand White rabbits.

Executive summary:

The dermal irritation potential of 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-) was estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

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-) was estimated to be not irritating to the skin of New Zealand White rabbits.

Based on the estimated results, 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-) can be considered to be not irritating to skin and can be classified under the category “Not Classified” as per CLP regulation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

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 from OECD QSAR toolbox v3.3 and the QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done 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

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

no data available

Vehicle:

not specified

Controls:

not specified

Amount / concentration applied:

100mg

Duration of treatment / exposure:

24 hours

Observation period (in vivo):

72 hours

Duration of post- treatment incubation (in vitro):

no data available

Number of animals or in vitro replicates:

3

Details on study design:

no data available

Other effects / acceptance of results:

no data available

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

72 h

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

no signs of irritation observed

Estimation method: Takes mode value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

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

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 Moderate binder, OH grooup OR Non binder, impaired OH or NH2 group OR Non binder, without OH or NH2 group OR Strong binder, NH2 group OR Strong binder, OH group OR Very strong binder, OH group OR Weak binder, OH group by Estrogen Receptor Binding

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OASIS v1.3

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Ester aminolysis OR Acylation >> Ester aminolysis >> Amides OR SNAr OR SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds OR SNAr >> Nucleophilic aromatic substitution on activated aryl and heteroaryl compounds >> Activated aryl and heteroaryl compounds by Protein binding by OASIS v1.3

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OECD

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Direct Acylation Involving a Leaving group OR Acylation >> Direct Acylation Involving a Leaving group >> Acetates by Protein binding by OECD

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Ac-SN2 AND Ac-SN2 >> Acylation involving an activated (glucuronidated) sufonamide group AND Ac-SN2 >> Acylation involving an activated (glucuronidated) sufonamide group >> Arenesulphonamides AND AN2 AND AN2 >> Nucleophilic addition at polarized N-functional double bond AND AN2 >> Nucleophilic addition at polarized N-functional double bond >> Arenesulphonamides by Protein binding alerts for Chromosomal aberration by OASIS v1.1

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as AN2 >> Michael addition to the quinoid type structures >> N-Subsituted Aromatic Amines by Protein binding alerts for Chromosomal aberration by OASIS v1.1

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Ac-SN2 AND Ac-SN2 >> Acylation involving an activated (glucuronidated) sufonamide group AND Ac-SN2 >> Acylation involving an activated (glucuronidated) sufonamide group >> Arenesulphonamides AND AN2 AND AN2 >> Nucleophilic addition at polarized N-functional double bond AND AN2 >> Nucleophilic addition at polarized N-functional double bond >> Arenesulphonamides by Protein binding alerts for Chromosomal aberration by OASIS v1.1

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as AN2 >> Michael-type addition to quinoid structures >> Phenols by Protein binding alerts for Chromosomal aberration by OASIS v1.1

Domain logical expression index: "m"

Similarity boundary:Target: CNS(=O)(=O)c1ccc2c(c1)ccc1c2N2=Nc3ccc(N(=O)=O)cc3O{-}.[Co]{2+}223(N1)Nc1ccc4cc(S(=O)(=O)O{-}.[Na]{+})ccc4c1N2=Nc1ccc(N(=O)=O)cc1O{-}.3
Threshold=10%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 858 Da

Domain logical expression index: "o"

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

Interpretation of results:

other: not irritating

Conclusions:

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-) was estimated to be not irritating to the eyes of New Zealand White rabbits.

Executive summary:

The ocular irritation potential of 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-) was estimated using OECD QSAR toolbox v3.3 with logPow as the primary descriptor.

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-) was estimated to be not irritating to the eyes of New Zealand White rabbits.

Based on the estimated results, 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-) can be considered to be not irritating to eyes and can be classified under the category “Not Classified” as per CLP regulation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation:

In different studies, 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-) has been investigated for potential for dermal irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits along with predicted data for target chemical and its structurally similar read across chemicals, Aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex (CAS No: 15790-07-5) and disodium 4-[(E)-2-(4-methyl-2-sulfophenyl)diazen-1-yl]-3-oxidonaphthalene-2-carboxylate(D&C Red 6)[CAS: 5858-81-1].The predicted data using the OECD QSAR toolbox has also been compared with the experimental data.

In a prediction done by SSS (2018) using the OECD QSAR toolbox v3.3 with log kow as the primary descriptor, the dermal irritation potential 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-). 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-) was estimated to be not irritating to the skin of New Zealand White rabbits.

This is supported by a dermal irritation study conducted(Sustainability Support Services (Europe) AB has letter of access, 2013) on New Zealand white rabbits in accordance with OECD 404 to assess the irritation parameter of the structurally similar read across chemical, aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS No: 15790-07-5].

3 female New Zealand White rabbits were used for the study. The animals were prepared 24 hours prior to application of test product. The furs from the dorsal area of trunk of animals were removed with electric clippers exposing an area measuring approximately 6 cm2 of body surface area of animal. The care was taken such that abrasion penetrated the Stratum corneum only and not dermis. 500gm (0.5g) of test compound was applied on a small area (approximately 6 cm2) of intact skin site. Each site of application was covered with impervious dressing which was secured in position with adhesive tape. The intact skin site of application of each animal was observed for signs of erythema and oedema at 60 min., 24, 48 and 72 hours after application and the responses were scored according to Draize method.

The Primary Irritation Index (PII) for aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS: 15790-07-5]after 14 days of observation was 0.0.Alsoaluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS: 15790-07-5] did not produce pain and any clinical signs of toxicity throughout the examination period of 14 days.

Hence, under the test conditions, aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS: 15790-07-5] can be concluded to be not irritating to New Zealand White rabbit skin.

The above results are supported by a study performed by JAMES E. FULTON, JR (J. Soc. Cosmet. Chem., 40, 321-333 (November/December 1989)) to determine the Comedogenicity and irritancy potential of the structurally similar read across chemical, disodium 4-[(E)-2-(4-methyl-2-sulfophenyl)diazen-1-yl]-3-oxidonaphthalene-2-carboxylate(D&C Red 6)[CAS: 5858 -81-1]. The dyes were mixed in propylene glycol at a 9 to 1 dilution for testing unless otherwise indicated (10% concentration). A colony of New Zealand albino rabbits that have genetically good ears and free from mites were used. Three rabbits, weighing two to three kilograms, were used for each assay. Animals were housed singly in suspended cages and fed Purina Rabbit Chow and water ad libitum. Animals were maintained on a 12-hour light and 12-hour dark cycle. A dose of 1 ml of the test material was applied and spread once daily to the entire inner surface of once for five days per week for two weeks. The opposite untreated ear of each animal served as an untreated control. The irritancy produced by repeated application of the chemical on the surface epidermis in the rabbit ear is evaluated on a scale of 0 to 5. The grades are summarized as follows:

 0 = No irritation; 1 = few scales, no Erythema; 2 = diffuse scaling, no Erythema; 3 = Generalized scaling with Erythema; 4 = Scaling, Erythema and Edema; 5 = Epidermal necrosis and slough.

D&C Red 6 falls under Grade 0 (no irritation observed). Hence it can be concluded that D&C Red 6 was not irritating to rabbit ears.

Based on the available data for the target as well as read across substances and applying the weight of evidence approach,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-)was not irritating to skin.Comparing the above annotations with the criteria of CLP regulation, test chemical can be classified under the category “Not Classified”.

Eye Irritation:

In different studies, 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-) has been investigated for potential for ocular irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits along with predicted data for target chemical and its structurally similar read across chemicals, Aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex (CAS No: 15790-07-5) and disodium 4-[(E)-2-(4-methyl-2-sulfophenyl)diazen-1-yl]-3-oxidonaphthalene-2-carboxylate(D&C Red 6)[CAS: 5858-81-1].The predicted data using the OECD QSAR toolbox has also been compared with the experimental data.

In a prediction done by SSS (2018) using the OECD QSAR toolbox v3.3 with log kow as the primary descriptor, the ocular irritation potential 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-). 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-) was estimated to be not irritating to the eyes of New Zealand White rabbits.

This is supported by An ocular irritation study conducted (Sustainability Support Services (Europe) AB has letter of access, 2013) on New Zealand white rabbits in accordance with OECD 405 to assess the irritation parameter of aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS: 15790-07-5]. 3 female New Zealand White rabbits were used for the study. 0.1g of the undiluted test chemical was instilled in the conjunctival sac of rabbits after gently pulling the lower lid away from the eyeball. The other eye which remained untreated served as a control. The ocular lesions were evaluated at 1, 24, 48 and 72 hours after the treatment. The grades of ocular reactions (conjunctiva, cornea and iris) were recorded at each observation. To determine the reversibility of the effect the animals were observed normally for 21 days. Any other lesions in the eye viz pannus, staining were observed and scored accordingly. Examination of reactions was facilitated by use of biomicroscope and hand slit lamp. Individual animal weights before and during the study was observed.

The overall irritation index of aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS: 15790-07-5] was 0.0 after 72 hours.

Also aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS: 15790-07-5] did not produce any clinical signs of toxicity throughout the examination period of 21 days.

Hence, under the test conditions, aluminium, 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid complex [CAS: 15790-07-5] can be concluded  to be not irritating to New Zealand White rabbit eyes.

These results are supported by the experimental study summarized in GESTIS SUBSTANCE Database (information system in hazardous substance of the Berufsgenossenscheftn), 2017; for the structurally similar read across chemical, disodium 4-[(E)-2-(4-methyl-2-sulfophenyl)diazen-1-yl]-3-oxidonaphthalene-2-carboxylate(D&C Red 6)[CAS: 5858-81-1]. Rabbits received(number not specified) 2 installation of 0.2 ml of a 10% D & C Red No. 6 aqueous suspension into the conjunctival sac of rabbits 5 times per week for 4 weeks. The chemical produced only minimal irritative effects after 2 hours which could not confirm the irritation potential. Hence, on the basis of findings D & C Red No. 6 (CAS no: 5858-81-1)can be considered as not irritating to the rabbits’ eye.

Based on the available data for the target as well as read across substances and applying the weight of evidence approach,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-)was not irritating to eyes.Comparing the above annotations with the criteria of CLP regulation, test chemical can be classified under the category “Not Classified”.

Justification for classification or non-classification

Based on the available information, 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-) is not likely to cause any irritation to eyes and skin. Hence, 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-) can be classified under the category “Not Classified” as per CLP regulation.