4'-aminoazobenzene-4-sulphonic acid

Endpoint summary

Description of key information

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the skin sensitization potential of the test chemical. Based on the summarized studies,it can be concluded that the testchemical is unable to cause skin sensitization and considered as not sensitizing. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Not Classified”.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

experimental data of test substances

Justification for type of information:

Data for the target chemical is summarized based on the available studies

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

WoE report is based on skin sensitization studies as- WoE-2, WoE-3 and WoE-4.
Skin sensitization studies were condcuted on humans and guinea pigs to assess its skin sensitizing effects.

GLP compliance:

not specified

Type of study:

patch test

Justification for non-LLNA method:

not specified

Species:

other: Human

Strain:

other: not applicable

Sex:

male/female

Route:

other: 1.epicutaneous, occlusive

Vehicle:

other: White petrolatum

Concentration / amount:

2%

Day(s)/duration:

2 days

Adequacy of induction:

not specified

Route:

other: 2.epicutaneous, occlusive

Vehicle:

other: White petrolatum

Concentration / amount:

No data available

Day(s)/duration:

24 hours

Adequacy of induction:

not specified

Route:

other: 3.intradermal and epicutaneous

Vehicle:

arachis oil

Concentration / amount:

INTRADERMAL : 0.1ml Freund’s complete adjuvant in water, test chemical 1% w/v in arachis oil, and Freund’s + test chemical 1% w/v in arachis oil (1:1) into three separate sites

TOPICAL: 0.2 – 0.3 ml test chemical 50% w/w in arachis oil

Day(s)/duration:

48 hours

Adequacy of induction:

not specified

No.:

#1

Route:

other: 1.epicutaneous, occlusive

Vehicle:

other: 1.White petrolatum

Concentration / amount:

2%

Day(s)/duration:

2 days

Adequacy of challenge:

not specified

No.:

#1

Route:

other: 2.epicutaneous, occlusive

Vehicle:

other: White petrolatum

Concentration / amount:

Not specified

Day(s)/duration:

24 hours

Adequacy of challenge:

not specified

No.:

#1

Route:

other: 3.epicutaneous, occlusive

Vehicle:

arachis oil

Concentration / amount:

0.1-0.2 ml test chemical 25 and 10% w/w in arachis oil

Day(s)/duration:

21 days

Adequacy of challenge:

not specified

No. of animals per dose:

1.32 patients
2.200 subjects
3.20 test; 10 negative control

Details on study design:

1.A patch contain test chemical was placed in a small squares (about 1.0 cm2) and wetted with 1 drop of tap water, water was used to imitate the circumstances (wet hands or sweating of hands). By this procedure a slight but visible yellow stain on the skin was found at the test site after 2 days of application, indicating liberation of the dyes.

2. MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: no data
- Exposure period:24 hours
- Test groups: 200 subjects
- Control group: no data
- Site: volvar forearms
- Frequency of applications:
- Duration: 10 alternate days
- Concentrations: no data

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: after 14 days
- Exposure period: 24 hours
- Test groups: 200 subjects
- Control group:
- Site: scapular backs
- Concentrations: no data
- Evaluation (hr after challenge): after 24 hours

3.MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 1
- Exposure period: 1 week
- Topical: 48 hours
- Test groups: 20
- Control group: 10
- Site: intradermal : three separate sites.
- Duration: Intradermal-1 week
Topical-48 hours
- Concentrations:
INTRADERMAL
•0.1ml Freund’s complete adjuvant in Water
•HR 92/103089 ((Phenylbenzimidazole Sulfonic Acid ) 1% w/v in arachis oil.
•Freund’s + HR 92/103089 1% w/v in arachis oil (1:1)

TOPICAL
After 1 week, a single topical application of 0.2 – 0.3 ml HR 92/103089 50% w/w in arachis oil under occlusion for 48 hours.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: On day 21
- Exposure period: No Data Available
- Test groups: 20
- Control group: 10
- Site: No Data Available
- Concentrations: 0.1-0.2 ml HR 92/103089 25 and 10% w/w in arachis oil.
- Evaluation (hr after challenge): No data available.

Challenge controls:

1.30 patients with an allergic contact dermatitis but negative to p- p-aminoazobenzene and PPD were also tested with the same patch test series.
2.Not specified
3.no data availble

Key result

Reading:

other: 1. 1st reading

Hours after challenge:

72

Group:

test chemical

Dose level:

2%

No. with + reactions:

0

Total no. in group:

32

Clinical observations:

The chemical did not elicit a positive patch test reaction in any one of the 32 patients’ positive to p-aminoazobenzene nor in the 30 control subjects.

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

other: 2.1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

Not specified

No. with + reactions:

0

Total no. in group:

200

Clinical observations:

None of the subjects showed any signs of contact sensitization.

Remarks on result:

no indication of skin sensitisation

Reading:

other: 3.1st reading

Group:

test chemical

Dose level:

0.1-0.2 ml test chemical 25 and 10% w/w in arachis oil

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

None of the treated animals had developed contact sensitization.

Remarks on result:

no indication of skin sensitisation

Interpretation of results:

other: Not sensitizing

Conclusions:

The test chemical was unable to cause skin sensitization and hence can be considered to be not sensitizing to the skin.

Executive summary:

Various studies were performed on humans and guinea pigs to assess the dermal sensitization potential of Test chemical. The studies are summarized as follows:

   

The patch test for test chemical was performed by peer reviewed journal in 32 patients with an established p-aminoazobenzene allergy. The test was conducted on a group of 32 patients with presumable allergic contact dermatitis and all with a positive patch teat reaction to p-aminoazobenzene (0.25% pet). The group consisted of 20 women (mean age 39.9 years) and men (mean age 46.6 years). 11 patients had previously also shown sensitization to PPD (Para-phenyldiamine). 30 patients with an allergic contact dermatitis but negative to p-aminoazobenzene and PPD were also tested with the same patch test series. A patch with test chemical was placed in small squares (about 1.0 cm2) and wetted with 1 drop of tap water, water was used to imitate the circumstances (wet hands or sweating of hands). By this procedure a slight but visible yellow stain on the skin was found at the test site after 2 days of application, indicating liberation of the dyes.The chemical did not elicit a positive patch test reaction in any one of the 32 patients’ positive to p-aminoazobenzene nor in the 30 control subjects. Hence the test chemical was considered to be not sensitizing.

 

The above results were supported by the Draize-Shelanski repeated insult patch test conducted by authoritative database on 200 human subjects for test chemical. In this study, the chemical applied to the subjects’ volvar forearms (200 subjects) as an aqueous solution for 10 alternate days, for 24-hour periods, followed by a 14-day rest period. Challenge batches were then applied under occlusion to fresh skin sites on the subjects scapular backs for 24 hours. The colour did not produce either irritation or allergic responses during the induction phase nor contact dermatitis in the challenge period. Therefore the test chemical was considered to be not sensitizing in a Draize-Shelanski repeated insult patch test conducted on 200 human subjects.

 

 

The above results were further supported by the skin sensitization study conducted according to OECD guideline 406 on guinea pigs by Magnusson and Kligman test to determine its sensitization potential of test chemical. 20 test group and 10 negative control groups were used in this study. Intradermal injections of 0.1ml Freund’s complete adjuvant in water, test chemical 1% w/v in arachis oil, and Freund’s + test chemical 1% w/v in arachis oil (1:1) into three separate sites. After 1 week, a single topical application of 0.2 – 0.3 ml test chemical 50% w/w in arachis oil under occlusion for 48 hours. On day 21 animals were challenged with 0.1-0.2 ml test chemical 25 and 10% w/w in arachis oil. No reactions were observed. Thus, from the study it can be concluded that the test substance is not a skin sensitizer.

 

All these studies lead to a conclusion that the Test chemical is indeed not sensitizing to skin. Hence, comparing the above annotations with the criteria of CLP regulation, Test chemical can be classified under the category “Not Classified”.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the skin sensitization potential of the test chemical. The studies are as mentioned below:

   

The patch test for test chemical was performed by peer reviewed journal in 32 patients with an established p-aminoazobenzene allergy. The test was conducted on a group of 32 patients with presumable allergic contact dermatitis and all with a positive patch teat reaction to p-aminoazobenzene (0.25% pet). The group consisted of 20 women (mean age 39.9 years) and men (mean age 46.6 years). 11 patients had previously also shown sensitization to PPD (Para-phenyldiamine). 30 patients with an allergic contact dermatitis but negative to p-aminoazobenzene and PPD were also tested with the same patch test series. A patch with test chemical was placed in small squares (about 1.0 cm2) and wetted with 1 drop of tap water, water was used to imitate the circumstances (wet hands or sweating of hands). By this procedure a slight but visible yellow stain on the skin was found at the test site after 2 days of application, indicating liberation of the dyes.The chemical did not elicit a positive patch test reaction in any one of the 32 patients’ positive to p-aminoazobenzene nor in the 30 control subjects. Hence the test chemical was considered to be not sensitizing.

 

The above result was supported by the Draize-Shelanski repeated insult patch test conducted by authoritative database on 200 human subjects for test chemical. In this study, the chemical applied to the subjects’ volvar forearms (200 subjects) as an aqueous solution for 10 alternate days, for 24-hour periods, followed by a 14-day rest period. Challenge batches were then applied under occlusion to fresh skin sites on the subjects scapular backs for 24 hours. The colour did not produce either irritation or allergic responses during the induction phase nor contact dermatitis in the challenge period. Therefore the test chemical was considered to be not sensitizing in a Draize-Shelanski repeated insult patch test conducted on 200 human subjects.

 

 

The overall results were further supported by the skin sensitization study conducted according to OECD guideline 406 on guinea pigs by Magnusson and Kligman test to determine its sensitization potential of test chemical. 20 test group and 10 negative control groups were used in this study. Intradermal injections of 0.1ml Freund’s complete adjuvant in water, test chemical 1% w/v in arachis oil, and Freund’s + test chemical 1% w/v in arachis oil (1:1) into three separate sites. After 1 week, a single topical application of 0.2 – 0.3 ml test chemical 50% w/w in arachis oil under occlusion for 48 hours. On day 21 animals were challenged with 0.1-0.2 ml test chemical 25 and 10% w/w in arachis oil. No reactions were observed. Thus, from the study it can be concluded that the test substance is not a skin sensitizer.

 

Based on the above summarized studies for target chemical and its structurally and functionally similar read across substances,it can be concluded that the testchemical is unable to cause skin sensitization and considered as non-skin sensitizer. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Not Classified”.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The skin sensitization potential of test substance andits structurally and functionally similar read across substanceswere observed in various studies. From the results obtained from these studies it is concluded that the chemical is not likely to cause skin sensitization and hence can be classified as non-skin sensitizer.