Registration Dossier

Skin Irritation:

The dermal irritation potential of 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated using OECD QSAR toolbox version 3.4 with logPow as the primary descriptor.

2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the skin of New Zealand White rabbits.

Based on the estimated result; 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile can be considered not irritating to skin and can be classified under the category “Not classified” as per CLP regulation.

Eye Irritation:

The ocular irritation potential of 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated using OECD QSAR toolbox version 3.4 with logPow as the primary descriptor.

2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the eyes of New Zealand White rabbits.

Based on the estimated results, 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile can be considered not irritating to eyes and can be classified under the category “Not Classified” as per CLP regulation.

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 v3.4 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 v3.4

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile
- IUPAC name: 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile
- Molecular formula: C18H19N5O4
- Molecular weight: 369.38 g/mole
- Smiles Notation: Cc1cc(N(CCO)CCO)ccc1N=Nc1ccc(N(=O)=O)cc1C#N
- Substance type: Organic
- Physical state: Solid powder (violet)

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:

clipped

Vehicle:

not specified

Controls:

not specified

Amount / concentration applied:

0.5g

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3

Details on study design:

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 8 nearest neighbours
Domain logical expression:Result: In Domain

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

Domain logical expression index: "a"

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 OR SN1 >> Nitrenium Ion formation >> Tertiary aromatic amine by DNA binding by OECD ONLY

Domain logical expression index: "b"

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) >> 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.1.4 ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Non binder, without OH or NH2 group 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, MW>500 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 v1.4

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group >> Carboxylic Acid Amides OR Acylation >> Acylation involving an activated (glucuronidated) ester group OR Acylation >> Acylation involving an activated (glucuronidated) ester group >> Arenecarboxylic Acid Esters OR Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group OR Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group >> Arenesulfonamides OR Acylation >> Direct acylation involving a leaving group OR Acylation >> Direct acylation involving a leaving group >> Carboxylic Acid Amides OR Acylation >> Ester aminolysis OR Acylation >> Ester aminolysis >> Amides OR AN2 OR AN2 >> Michael addition to activated double bonds OR AN2 >> Michael addition to activated double bonds >> alpha,beta-Unsaturated Carbonyls and Related Compounds OR AN2 >> Michael type addition to activated double bond of pyrimidine bases OR AN2 >> Michael type addition to activated double bond of pyrimidine bases >> Pyrimidines and Purines OR AN2 >> Michael-type addition to quinoid structures OR AN2 >> Michael-type addition to quinoid structures >> Carboxylic Acid Amides OR AN2 >> Michael-type addition to quinoid structures >> N-Substituted Aromatic Amines OR AN2 >> Nucleophilic addition at polarized N-functional double bond OR AN2 >> Nucleophilic addition at polarized N-functional double bond >> Arenesulfonamides OR AN2 >> Schiff base formation with carbonyl group of pyrimidine and purine bases OR AN2 >> Schiff base formation with carbonyl group of pyrimidine and purine bases >> Pyrimidines and Purines OR Michael addition OR Michael addition >> Michae addition on quinoide type compounds OR Michael addition >> Michae addition on quinoide type compounds >> Quinone methide(s)/imines; Quinoide oxime structure; Nitroquinones, Naphthoquinone(s)/imines OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group >> Activated electrophilic ethenylarenes OR Nucleophilic addition OR Nucleophilic addition >> Addition to carbon-hetero double bonds OR Nucleophilic addition >> Addition to carbon-hetero double bonds >> Ketones OR Schiff base formation OR Schiff base formation >> Schiff base formation with carbonyl compounds OR Schiff base formation >> Schiff base formation with carbonyl compounds >> Aldehydes OR SN2 OR SN2 >> Nucleophilic substitution at sp3 carbon atom OR SN2 >> Nucleophilic substitution at sp3 carbon atom >> alpha-Activated haloalkanes OR SN2 >> SN2 Reaction at a sp3 carbon atom OR SN2 >> SN2 Reaction at a sp3 carbon atom >> Activated alkyl esters and thioesters 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 v1.4

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Reactive unspecified by Acute aquatic toxicity MOA by OASIS ONLY

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as (!Undefined)Group All Lipid Solubility < 0.01 g/kg AND (!Undefined)Group CN Lipid Solubility < 0.4 g/kg AND Group All Melting Point > 200 C AND Group CN Aqueous Solubility < 0.1 g/L AND Group CN Melting Point > 180 C AND Group CN Molecular Weight > 290 g/mol AND Group CN Vapour Pressure < 0.001 Pa by Skin irritation/corrosion Exclusion rules by BfR

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as (!Undefined)Group CNS Surface Tension > 62 mN/m OR Group All log Kow < -3.1 OR Group CN Aqueous Solubility < 0.0001 g/L OR Group CN log Kow > 4.5 OR Group CN log Kow > 5.5 OR Group CNS log Kow < 0.5 OR Group CNS log Kow < -2 OR Group CNS Melting Point > 120 C OR Group CNS Melting Point > 50 C by Skin irritation/corrosion Exclusion rules by BfR

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of log Kow which is >= 1.57

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of log Kow which is <= 5.92

Interpretation of results:

other: not irritating

Conclusions:

2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the skin of New Zealand White rabbits.

Executive summary:

The dermal irritation potential of 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated using OECD QSAR toolbox version 3.4 with logPow as the primary descriptor.

2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the skin of New Zealand White rabbits.

Based on the estimated result; 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile can be considered not irritating to skin and can be classified under the category “Not classified” as per CLP regulation.

Endpoint conclusion:

no adverse effect observed (not irritating)

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 v3.4 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 v3.4

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile
- IUPAC name: 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile
- Molecular formula: C18H19N5O4
- Molecular weight: 369.38 g/mole
- Smiles Notation: Cc1cc(N(CCO)CCO)ccc1N=Nc1ccc(N(=O)=O)cc1C#N
- Substance type: Organic
- Physical state: Solid powder (violet)

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:

0.1g

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

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

Estimation method: Takes mode value from the 9 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 ( not "o") ) ) and ("p" and ( not "q") ) ) and ("r" and "s" ) )

Domain logical expression index: "a"

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 OR SN1 >> Nitrenium Ion formation >> Tertiary aromatic amine by DNA binding by OECD ONLY

Domain logical expression index: "b"

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) >> 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.1.4 ONLY

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as No alert found by Protein binding by OASIS v1.4

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Acylation OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group OR Acylation >> Acylation involving an activated (glucuronidated) carboxamide group >> Carboxylic Acid Amides OR Acylation >> Acylation involving an activated (glucuronidated) ester group OR Acylation >> Acylation involving an activated (glucuronidated) ester group >> Arenecarboxylic Acid Esters OR Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group OR Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group >> Arenesulfonamides OR Acylation >> Direct acylation involving a leaving group OR Acylation >> Direct acylation involving a leaving group >> Carboxylic Acid Amides OR Acylation >> Ester aminolysis OR Acylation >> Ester aminolysis >> Amides OR AN2 OR AN2 >> Michael addition to activated double bonds OR AN2 >> Michael addition to activated double bonds >> alpha,beta-Unsaturated Carbonyls and Related Compounds OR AN2 >> Michael type addition to activated double bond of pyrimidine bases OR AN2 >> Michael type addition to activated double bond of pyrimidine bases >> Pyrimidines and Purines OR AN2 >> Michael-type addition to quinoid structures OR AN2 >> Michael-type addition to quinoid structures >> Carboxylic Acid Amides OR AN2 >> Michael-type addition to quinoid structures >> Hydroxylated Phenols OR AN2 >> Michael-type addition to quinoid structures >> N-Substituted Aromatic Amines OR AN2 >> Michael-type addition to quinoid structures >> Substituted Anilines OR AN2 >> Michael-type addition to quinoid structures >> Substituted Phenols OR AN2 >> Nucleophilic addition at polarized N-functional double bond OR AN2 >> Nucleophilic addition at polarized N-functional double bond >> Arenesulfonamides OR AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) OR AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) >> Heterocyclic Aromatic Amines OR AN2 >> Schiff base formation with carbonyl group of pyrimidine and purine bases OR AN2 >> Schiff base formation with carbonyl group of pyrimidine and purine bases >> Pyrimidines and Purines OR Michael addition OR Michael addition >> Michae addition on quinoide type compounds OR Michael addition >> Michae addition on quinoide type compounds >> Quinone methide(s)/imines; Quinoide oxime structure; Nitroquinones, Naphthoquinone(s)/imines OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group >> Activated electrophilic ethenylarenes OR Michael addition >> Michael addition on polarised Alkenes OR Michael addition >> Michael addition on polarised Alkenes >> alpha,beta-Unsaturated oximes OR Nucleophilic addition OR Nucleophilic addition >> Addition to carbon-hetero double bonds OR Nucleophilic addition >> Addition to carbon-hetero double bonds >> Ketones OR Radical reactions OR Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base OR Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines OR Schiff base formation OR Schiff base formation >> Schiff base formation with carbonyl compounds OR Schiff base formation >> Schiff base formation with carbonyl compounds >> Aldehydes OR Schiff base formation >> Schiff base formation with carbonyl compounds >> Aromatic carbonyl compounds OR SE reaction (CYP450-activated heterocyclic amines) OR SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base OR SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines OR SN1 OR SN1 >> Carbenium ion formation (enzymatic) OR SN1 >> Carbenium ion formation (enzymatic) >> Carbenium ion OR SN2 OR SN2 >> SN2 Reaction at a sp3 carbon atom OR SN2 >> SN2 Reaction at a sp3 carbon atom >> Activated alkyl esters and thioesters 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 OR SR reaction (peroxidase-activated heterocyclic amines) OR SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base OR SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines by Protein binding by OASIS v1.4

Domain logical expression index: "e"

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

Domain logical expression index: "f"

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: "g"

Referential boundary: The target chemical should be classified as Known precedent reproductive and developmental toxic potential AND NO2-alkyl/NO2-benzene derivatives (8b) AND Toluene and small alkyl toluene derivatives (8a) by DART scheme v.1.0

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Dihalogen-, dinitro-phenol and their ester derivatives (8e) OR Not covered by current version of the decision tree OR Not known precedent reproductive and developmental toxic potential OR Organophosphorus compounds (1b) OR Polyhalogenated benzene derivatives (8c) by DART scheme v.1.0

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Aromatic diazo (Genotox) AND Nitro-aromatic (Genotox) AND Structural alert for genotoxic carcinogenicity by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Aromatic mono-and dialkylamine (Genotox) OR No alert found by Carcinogenicity (genotox and nongenotox) alerts by ISS

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Inclusion rules not met by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Phenols OR Sulfonic acids or their salts by Skin irritation/corrosion Inclusion rules by BfR

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Bioavailable by Lipinski Rule Oasis ONLY

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Alcohol AND Alkyl arenes AND Aromatic amine AND Aryl AND Azo AND Nitrile AND Nitrobenzene by Organic Functional groups

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Carboxylic acid by Organic Functional groups

Domain logical expression index: "p"

Referential boundary: The target chemical should be classified as Not categorized by Repeated dose (HESS)

Domain logical expression index: "q"

Referential boundary: The target chemical should be classified as Nitrobenzenes (Testicular toxicity) Rank C by Repeated dose (HESS)

Domain logical expression index: "r"

Parametric boundary:The target chemical should have a value of log Kow which is >= 0.927

Domain logical expression index: "s"

Parametric boundary:The target chemical should have a value of log Kow which is <= 4.37

Interpretation of results:

other: not irritating

Conclusions:

2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the eyes of New Zealand White rabbits.

Executive summary:

The ocular irritation potential of 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated using OECD QSAR toolbox version 3.4 with logPow as the primary descriptor.

2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the eyes of New Zealand White rabbits.

Based on the estimated results, 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile can be considered not irritating to eyes and can be classified under the category “Not Classified” as per CLP regulation.

Endpoint conclusion:

no adverse effect observed (not irritating)

Endpoint conclusion:

no study available

Skin Irritation:

Various studies have been investigated for the test chemical, 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile to observe the potential for dermal irritation to a greater or lesser extent.These studies include in vivo studies in rabbits along with predicted data for the target chemical and its structurally similar read across substances, 2,2'-[[4-[(4-aminophenyl)azo]phenyl]imino]bisethanol (Disperse Black 9)[CAS: 20721-50-0] and 2,2'-({3-methyl-4-[(4-nitrophenyl)diazenyl]phenyl}imino)diethanol(Disperse Red 17)[CAS: 3179-89-3].The experimental results are also supported by theresults obtained from OECD QSAR toolbox.

In a prediction done by SSS (2018) using the OECD QSAR toolbox v3.4 with log kow as the primary descriptor, the dermal irritation potential was estimated for2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile. 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the skin of New Zealand White rabbits.

This is supported by the experimental study summarized in JOURNAL OF THE AMERICAN COLLEGE OF TOXICOLOGY, Volume 5, Number 3, 1986; for thestructurally similar read across substance, 2,2'-[[4-[(4-aminophenyl)azo]phenyl]imino]bisethanol (Disperse Black 9)[CAS: 20721-50-0].0.5 ml of semi permanent dye containing 0.38% (wt/wt) Disperse Black 9 was applied to the intact skin of 6 rabbits and observed for signs of irritation. The dermal reactions were observed and scored at 24 and 72 hours. The maximum score for dermal reactions was 4.

No signs of irritation were noted on the rabbit skin. The primary irritation index was reported to be 0.0.

Based on the scores and observations, Disperse Black 9 can be considered not irritating to rabbit skin.

The above results are supported by the experimental study summarized in COLIPA n° B5, adopted by the SCCNFP[Scientific Committee on Cosmetic Products and Non-Food Products intended for Consumers], June 2003; for the structurally similar read across substance, 2,2'-({3-methyl-4-[(4-nitrophenyl)diazenyl]phenyl}imino)diethanol(Disperse Red 17)[CAS: 3179-89 -3]. The study was performed in accordance with OECD 404 and 92/69/EEC. Annex V Guidelines.0.5 g of Disperse Red 17 moistened with water was applied to 6.25 cm² area of intact skin of 3 female New Zealand albino rabbits under semi-occlusive conditions for 4 hours. Remaining test substance was removed by swabbing with cotton wool swabs soaked in warm water. The skin was examined for erythema, eschar formation and edema at 1, 24, 48 and 72 hours after removal of the patches. An index of Cutaneous Primary Irritation was calculated from the mean scores at the sites and at each time point. No signs of irritation were noted on the rabbit skin. Red/orange staining was reported at all time points. The primary irritation index was reported to be 0.0.

Based on the scores and observations, Disperse Red 17 can be considered not irritating to rabbit skin.

Based on the available data for the target as well as read across chemicals and applying the weight of evidence approach, 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile can be considered to be 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:

Various studies have been investigated for the test chemical, 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile to observe the potential for ocular irritation to a greater or lesser extent.These studies include in vivo studies in rabbits along with predicted data for the target chemical and its structurally similar read across substances, 2,2'-[[4-[(4-aminophenyl)azo]phenyl]imino]bisethanol (Disperse Black 9)[CAS: 20721-50-0] and 1-(4-Methyl-2-nitrophenylazo)-2-naphthol(C.I. Pigment Red 3)[CAS: 2425-85-6].The experimental results are also supported by the results obtained from OECD QSAR toolbox.

In a prediction done by SSS (2018) using the OECD QSAR toolbox v3.4 with log kow as the primary descriptor, the ocular irritation potential was estimated for2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile. 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile was estimated to be not irritating to the eyes of New Zealand White rabbits.

This is supported by the experimental study summarized in JOURNAL OF THE AMERICAN COLLEGE OF TOXICOLOGY, Volume 5, Number 3, 1986; for thestructurally similar read across substance, 2,2'-[[4-[(4-aminophenyl)azo]phenyl]imino]bisethanol (Disperse Black 9)[CAS: 20721-50-0]. 100 mg of the powdered dye was instilled in one eye of 6 rabbits and the other eye served as control. The treated eyes were observed and scored at 1, 2, 3, and 7 days. The maximum attainable score was 110.

No signs of irritation were observed in the treated eyes of rabbits at any time point.

The scores obtained at 1, 2, 3, and 7 days were 0.0. Hence, Disperse Black 9 can be considered to be not irritating to rabbit eyes.

The above results are further supported by the experimental study summarized inScientific Committee on Cosmetology (seventh series), 1988; for the structurally similar read across substance,1-(4-Methyl-2-nitrophenylazo)-2-naphthol(C.I. Pigment Red 3)[CAS: 2425-85-6].Undiluted 100mg of C.I. Pigment Red 3 was installed into the eye of each rabbits which produced Slight conjunctival changes only after one hour.

Since the observed effects were cleared, the chemical C.I. Pigment Red 3(CAS No: 2425-85-6) was considered to be not irritating to the rabbits’ eye.

Based on the available data for the target as well as read across chemicals and applying the weight of evidence approach, 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile can be considered to be not irritating to eyes.Comparing the above annotations with the criteria of CLP regulation, test chemical can be classified under the category “Not Classified”.

Available data for 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile indicates that it is not likely to cause any irritation or corrosion to skin and eyes.

Hence, 2-[[4-[bis(2-hydroxyethyl)amino]-o-tolyl]azo]-5-nitrobenzonitrile can be classified under the category “Not Classified” as per CLP regulation.