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Diss Factsheets

Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
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.

Data source

Reference
Reference Type:
publication
Title:
Sensitization to azo dyes: negative patch tests to yellow and red azo dyes in printed paper
Author:
Thierbach MA, Geursen-Reitsma AM, van Joost T
Year:
1992
Bibliographic source:
Contact Dermatitis, 27, 22-26, (1992)

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: as mentioned below
Principles of method if other than guideline:
A patch test for chemical C. I. Pigment Yellow 12 (CAS no: 6358-85-6) was performed in 32 patients with an established p-aminoazobenzene allergy.
GLP compliance:
not specified
Type of study:
patch test
Justification for non-LLNA method:
not specified

Test material

Constituent 1
Reference substance name:
2,2'-[(3,3'-dichlorobiphenyl-4,4'-diyl)didiazene-2,1-diyl]bis(3-oxo-N-phenylbutanamide)
Cas Number:
6358-85-6
Molecular formula:
C32H26Cl2N6O4
IUPAC Name:
2,2'-[(3,3'-dichlorobiphenyl-4,4'-diyl)didiazene-2,1-diyl]bis(3-oxo-N-phenylbutanamide)
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material (as cited in study report): C. I. Pigment Yellow 12
- Molecular formula: C32H26Cl2N6O4
- Molecular weight: 629.5014 g/mol
- Substance type: organic
- Physical state: solid
Specific details on test material used for the study:
- Name of test material (as cited in study report): C. I. Pigment Yellow 12
- Molecular formula: C32H26Cl2N6O4
- Molecular weight: 629.5014 g/mol
- Substance type: organic
- Physical state: solid

In vivo test system

Test animals

Species:
other: Human
Strain:
other: Not specified
Sex:
male/female
Details on test animals and environmental conditions:
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).

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, occlusive
Vehicle:
other: White petrolatum
Concentration / amount:
2%
Day(s)/duration:
2 days
Adequacy of induction:
not specified
Challenge
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
other: White petrolatum
Concentration / amount:
2%
Day(s)/duration:
2 days
Adequacy of challenge:
not specified
No. of animals per dose:
32 patients
Details on study design:
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.
Challenge controls:
30 patients with an allergic contact dermatitis but negative to p- p-aminoazobenzene and PPD were also tested with the same patch test series.
Positive control substance(s):
not specified

Results and discussion

In vivo (non-LLNA)

Results
Reading:
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

In vivo (LLNA)

Cellular proliferation data / 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.

Applicant's summary and conclusion

Interpretation of results:
other: not sensitizing
Conclusions:
The chemical C. I. Pigment Yellow 12 (CAS no: 6358-85-6) 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 C. I. Pigment Yellow 12 (CAS no: 6358-85-6) was considered to be not sensitizing.
Executive summary:

A patch test for chemical C. I. Pigment Yellow 12 (CAS no: 6358-85-6) was performed 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 C. I. Pigment Yellow 12 (CAS no: 6358-85-6) was considered to be not sensitizing.