1-(4-methyl-2-nitrophenylazo)-2-naphthol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Old study available from the time where the non-LLNA study was not available

Test material

Test material information

Constituent 1

Reference substance name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

EC Number:

219-372-2

EC Name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

Cas Number:

2425-85-6

Molecular formula:

C17H13N3O3

IUPAC Name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Purity: 95.6%
Product code: HOE CG 0418 OD ZD96 0001

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Hoe: DHPK (SPFLac)

Sex:

female

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

petrolatum

Challenge

Route:

epicutaneous, semiocclusive

Vehicle:

petrolatum

No. of animals per dose:

10 amimals in the treatment group and 5 animals in the control

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1% C.I. Pigment Red 3 in petrolatum

No. with + reactions:

4

Total no. in group:

10

Clinical observations:

Very slight up to well-defined erythema and very slight oedema were observed in four animals

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1% C.I. Pigment Red 3 in petrolatum. No with. + reactions: 4.0. Total no. in groups: 10.0. Clinical observations: Very slight up to well-defined erythema and very slight oedema were observed in four animals.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1% C.I. Pigment Red 3 in petrolatum

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

One animal of the treated group showed very slight to well-defined erythema

Remarks on result:

other: see Remark

Remarks:

Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1% C.I. Pigment Red 3 in petrolatum. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: One animal of the treated group showed very slight to well-defined erythema.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Executive summary:

Testing for sensitizing properties of Pigment Red 3 was performed in female Guinea pigs according to the method of Magnusson & Kligman.

Intra dermal induction was performed using 0.2% Pigment Red 2 in semi-liquid paraffin. Dermal induction was carried out with 5%, challenge treatment with 1% Pigment Red 3 in petrolatum.

Four animals of the treatment group showed a positive skin response after the first challenge procedure and one animal reacted after the second challange. If the effects observed at the first challange are due to sensitization, then equal or even stronger reactions would be expected after the second challenge procedure. Therefore, the reactions noted in the three other animals at the first challange are considered to be rather unspecific irritation effects than allergic reactions.

Based on the results of this study Pigment Red 3 is not considered to be a skin sensitizer.