Registration Dossier

Administrative data

Description of key information

Skin irritation:

A patch test was performed in human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its irritation efficacy. The patch of 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was applied onto the back of each patient for 24 hours by usingFinn Chambers® on Scanpor® (Epitest, Ltd. Oy). After removal of patch, skin reactions were assessed according to the ICDRG classification for 2 days. Twenty-eight healthy female volunteers, aged 20 and 21, were also tested with the sample as controls. None gave a positive reaction. Since thepositive reactions were seen in 2 out of total 8 cases,the test chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6)was considered to be irritatingin human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R.

Eye irritation

An ocular irritation study was performed on rabbits for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its eye irritating effects. When pure1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was administrated into the eye of rabbits, slight ocular effects were observed. Hence the chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) was considered to be irritating to the rabbits’ eye.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records
Reference
Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
Data is from peer reviewed journal
Reference:
Composition 0
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
A patch test was performed in human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its irritation efficacy.
GLP compliance:
not specified
Test material information:
Composition 1
Specific details on test material used for the study:
- Name of test material (as cited in study report): C.I. Solvent orange 7
- Molecular formula: C18H16N2O
- Molecular weight : 276.337 g/mol
- Substance type: Organic
- Physical state: Solid
- Smiles : Cc1ccc(N=Nc2c(O)ccc3ccccc23)c(C)c1
- InChI: 1S/C18H16N2O/c1-12-7-9-16(13(2)11-12)19-20-18-15-6-4-3-5-14(15)8-10-17(18)21/h3-11,21H,1-2H3/b20-19
Species:
other: Human
Strain:
other: Not applicable
Details on test animals and environmental conditions:
No data available
Type of coverage:
occlusive
Preparation of test site:
not specified
Vehicle:
other: Petrolatum
Controls:
yes
Amount / concentration applied:
1%
Duration of treatment / exposure:
2 days
Observation period:
24 hours after patch removal
Number of animals:
8
Details on study design:
TEST SITE
- Area of exposure: back of each volunteers
- Type of wrap if used: Finn Chambers® on Scanpor® (Epitest, Ltd. Oy).
REMOVAL OF TEST SUBSTANCE
- Time after start of exposure:24 hours

SCORING SYSTEM: Readings were made according to the ICDRG classification (Wilkinson et a!. 1970)
Irritation parameter:
overall irritation score
Basis:
mean
Time point:
24 h
Score:
2
Max. score:
8
Reversibility:
not specified
Remarks on result:
positive indication of irritation
Remarks:
Readings were made according to the ICDRG classification (Wilkinson et a!. 1970) 24 h after the patches were removed.
Irritant / corrosive response data:
Two patients showed positive skin reaction.
Interpretation of results:
Category 2 (irritant) based on GHS criteria
Conclusions:
Positive reactions were seen in 2 out of total 8 cases. Thus the test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) was considered to be irritating in human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R.
Executive summary:

A patch test was performed in human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its irritation efficacy.

 

The patch of 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was applied onto the back of each patient for 24 hours by usingFinn Chambers® on Scanpor® (Epitest, Ltd. Oy). After removal of patch, skin reactions were assessed according to the ICDRG classification for 2 days.

 

Twenty-eight healthy female volunteers, aged 20 and 21, were also tested with the sample as controls. None gave a positive reaction.

 

Since thepositive reactions were seen in 2 out of total 8 cases,the test chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6)was considered to be irritating in human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Justification for type of information:
Data is from safety assessment report
Reference:
Composition 0
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
An ocular irritation study was performed on rabbits for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its eye irritating effects.
GLP compliance:
not specified
Test material information:
Composition 1
Specific details on test material used for the study:
- Name of test material (as cited in study report): C.I. Solvent orange 7
- Molecular formula: C18H16N2O
- Molecular weight : 276.337 g/mol
- Substance type: Organic
- Physical state: Solid
- Smiles : Cc1ccc(N=Nc2c(O)ccc3ccccc23)c(C)c1
- InChI: 1S/C18H16N2O/c1-12-7-9-16(13(2)11-12)19-20-18-15-6-4-3-5-14(15)8-10-17(18)21/h3-11,21H,1-2H3/b20-19+
Species:
rabbit
Strain:
not specified
Details on test animals or tissues and environmental conditions:
No data available
Vehicle:
unchanged (no vehicle)
Controls:
not specified
Amount / concentration applied:
100% (pure)
Duration of treatment / exposure:
No data available
Observation period (in vivo):
No data available
Duration of post- treatment incubation (in vitro):
No data available
Number of animals or in vitro replicates:
No data available
Details on study design:
No data available
Irritation parameter:
overall irritation score
Basis:
mean
Reversibility:
not specified
Remarks on result:
positive indication of irritation
Irritant / corrosive response data:
Slight irritating effects were observed in treated rabbits.
Interpretation of results:
Category 2 (irritating to eyes) based on GHS criteria
Conclusions:
The test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) was considered to be slightly irritating to the eye of rabbits.
Executive summary:

An ocular irritation study was performed on rabbits for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its eye irritating effects.

 

When pure1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was administrated into the eye of rabbits, slight ocular effects were observed. Hence the chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) was considered to be irritating to the rabbits’ eye.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Skin irritation:

Various studieshas been investigated for the test chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6)to observe the potential for dermal irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits and humans for target chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) and its structurally similar read across substances1-(phenyldiazenyl)-2-naphthol (CAS No: 842-07-9)and1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol (CAS No: 85-83-6)which have been summarized as below;

The Skin irritation study was performed byTAKEHITO KGZUKA, MINORU TASHIR0, SHIGEHARU SANO, KEIICHI FUJIMOTO, YUMI NAKAMURA, SEIICHI HASHIMOTO AND GEN NAKAMINAM (1980) in human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its irritation efficacy. The patch of 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was applied onto the back of each patient for 24 hours by usingFinn Chambers® on Scanpor® (Epitest, Ltd. Oy). After removal of patch, skin reactions were assessedaccording to the ICDRG classification for 2 days.Twenty-eight healthy female volunteers, aged 20 and 21, were also tested with the sample as controls. None gave a positive reaction. Since thepositive reactions were seen in 2 out of total 8 cases,the test chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6)was considered to be irritatingin theses human patients.

The above result was supported by experimental studies conducted byCommission of the European Communities(1988) fortest chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) and itsstructurally similar read across substances1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol (CAS No: 85-83-6) summarized as follows;

In the Skin irritation study performed on rabbits for 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6, each rabbit received 40% solution in PEG 400 or 200mg of undiluted1-[(2,4-dimethylphenyl)diazenyl]-2-naphtholunder occlusive condition and later skin reactions were examined.Slight erythema and oedema was observed in treated animals in both cases. Hence the chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) was considered to be irritating to the skin of rabbits under occlusive condition.

In next skin irritation study performed on rabbits for 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6), 0.1 ml of dilutions of 2, 1, 0.1 and 0.01% of 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was injected intradermally into the skin of the test animal. The treated rabbits showed indications of irritating properties. Thus chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) was considered to be irritating to the skin of rabbits when injected intradermally.

In theSkin irritation study performed for structurally similar read across substances1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol (CAS No: 85-83-6) on rabbits, the 1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol was applied dermally on to the skin of each rabbits at concentration of 500 mg in 0.5 mL 1,2-propanediol. The treated rabbits produced slight skin reaction with irritation index of 2.3. Hence the chemical 1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol (CAS No: 85-83-6) was considered to be irritating to the skin of rabbits.

TAKEHITO KGZUKA, MINORU TASHIR0, SHIGEHARU SANO, KEIICHI FUJIMOTO, YUMI NAKAMURA, SEIICHI HASHIMOTO AND GEN NAKAMINAM (1980) performed same study (mentioned above for target CAS) for anotherstructurally similar read across substances1-(phenyldiazenyl)-2-naphthol (CAS No: 842-07-9)in human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red Rwhich further supports the above results. In this test,thepositive reactions were seen in all 8 cases,thus chemical1-(phenyldiazenyl)-2-naphthol (CAS No: 842-07-9) was considered to be irritatingin human patients suffering from pigmented contact dermatitis caused by the commercial Brilliant Lake Red R.

Based on the available data for the targetchemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) and its structurally similar read across substances1-(phenyldiazenyl)-2-naphthol (CAS No: 842-07-9)and1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol (CAS No: 85-83-6),it can be concluded thatchemicalchemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) is able to cause skin irritation and considered as irritating.Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Category 2”.

Eye irritation

In different studies,the test chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) has been investigated to observe the potential for ocular irritation to a greater or lesser extent. The studies are based on in vivo experiments in rabbits for target chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) and its structurally similar read across substances1-[(2-methoxyphenyl)diazenyl]-2-naphthol(CAS No: 1229-55-6),Sudan IV (CAS No: 85-83-6)and Solvent Red 23 (CAS No: 85-86-9 )which have been summarized as below;

Commission of the European Communities(1988) performedan ocular irritation study on rabbits for test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) to assess its eye irritating effects.When pure1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol was administrated into the eye of rabbits, slight ocular effects were observed. Hence the chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) was considered to be irritating to the rabbits’ eye.

The above result was further supported by experimental study conducted by Gunda Reddy and Dale A. Mayhew (1996) and U.S. Army Medical Bioengineering Research and development Laboratory (1986) forstructurally similar read across substances1-[(2-methoxyphenyl)diazenyl]-2-naphthol(1229-55-6)on6 (3/sex) New Zealand White Albino rabbits. 0.1 g of neat1-[(2-methoxyphenyl)diazenyl]-2-naphthol was instilled into the eyes of rabbits and the effects were observed. The treated eye of each animal was examined for ocular irritation and lesions at 24, 48 and 72 hours (+2 hours at each interval). The treated eyes were evaluated on days 7, 14, and 21 if irritation persisted. No mortality and clinical signs of toxicity were observed in treated rabbits. Redness (grades 1 through 3), chemosis (grades I and 2), discharge (grades 1 and 2) and iritis (grade 1) were observed. Blistering of the conjunctivae were observed. Blistering of the conjunctivae was noted for all animals. Two animals also exhibited opacities and positive fluorescein staining. All animals were considered to have exhibited a positive response to1-[(2-methoxyphenyl)diazenyl]-2-naphthol.The mean irritation score after 72 hours was 0.7 Hence,1-[(2-methoxyphenyl)diazenyl]-2-naphthol(CAS No: 1229-55-6)can be considered to be irritating to New Zealand White rabbit eyes.

COMMISSION OF THE EUROPEAN COMMUNITIES (1988) carried out another eye irritation studies for itsstructurally similar read across substancesSudan IV (CAS No: 85-83-6 ) and Solvent Red 23 (CAS No: 85-86-9 ) in rabbits which further supports the above results and summarized as follows;

In an eye irritation test for Sudan IV (CAS No: 85-83-6), 100 mg of Sudan IV was made into a paste with 8 drops of 1,2-propanediol and instilled into the rabbits eyes The rabbits were observed (duration not specified) for ocular reactions to Sudan IV. The dye was classified as slightly irritating to the mucous membranes.

In next ocular irritation test for Solvent Red 23 (CAS No: 85-86-9), 0.1 g Solvent Red 23 with 2 drops of propanediol was placed into to the rabbit eyes. The chemical produced slight irritating effects and hence Solvent Red 23 (CAS No: 85-86-9) was considered to be irritating to rabbit eyes.

Based on the available data for the targetchemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) and its structurally similar read across substances1-[(2-methoxyphenyl)diazenyl]-2-naphthol(CAS No: 1229-55-6),Sudan IV (CAS No: 85-83-6)and Solvent Red 23 (CAS No: 85-86-9 ),it can be concluded thatchemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) is able to cause eye irritation and considered as irritating.Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Category 2”.

Justification for classification or non-classification

The skin and eye irritation potential of test chemical1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6) and its structurally similar read across substanceswere observed in various studies. The results obtained from these studies indicates that the test chemical 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6)is likely to cause skin and eye irritation. Hence 1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol (CAS No: 3118-97-6)can be classified under the category “Category 2” for skin and eye as per CLP.