Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 205-182-7 | CAS number: 135-19-3
Skin sensitisation
Administrative data
- Endpoint:
- skin sensitisation: in vivo (non-LLNA)
- Type of information:
- experimental study
- Remarks:
- GPMT
- Adequacy of study:
- key study
- Study period:
- 24.03.1992 - 24..04.1992
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 992
- Report date:
- 1992
Materials and methods
Test guidelineopen allclose all
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 406 (Skin Sensitisation)
- Version / remarks:
- 12.05.1981
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- EU Method B.6 (Skin Sensitisation)
- Deviations:
- no
- GLP compliance:
- yes
- Type of study:
- guinea pig maximisation test
- Justification for non-LLNA method:
- appropriate guinea pig maximisation test is available
Test material
- Reference substance name:
- 2-naphthol
- EC Number:
- 205-182-7
- EC Name:
- 2-naphthol
- Cas Number:
- 135-19-3
- Molecular formula:
- C10H8O
- IUPAC Name:
- 2-naphthol
- Test material form:
- solid
Constituent 1
In vivo test system
Test animals
- Species:
- guinea pig
- Strain:
- Pirbright-Hartley
- Remarks:
- Pirbright-White
- Sex:
- female
Study design: in vivo (non-LLNA)
Inductionopen allclose all
- Route:
- intradermal
- Vehicle:
- other: semi-liquid paraffin
- Concentration / amount:
- 2% solution of test substance in semi-liquid paraffin
- Day(s)/duration:
- day 1
- Adequacy of induction:
- not specified
- Route:
- epicutaneous, occlusive
- Vehicle:
- petrolatum
- Concentration / amount:
- 0,5 g via cellulose patch (2 x 4 cm)
- Day(s)/duration:
- day 8
- Adequacy of induction:
- not specified
Challenge
- No.:
- #1
- Route:
- epicutaneous, occlusive
- Vehicle:
- petrolatum
- Concentration / amount:
- 0,5 g via cellulose patch (2 x 2 cm)
- Day(s)/duration:
- day 22
- Adequacy of challenge:
- not specified
- No. of animals per dose:
- 10 animals in the treatment group and 5 animals in the control group were used.
- Details on study design:
- The concentrations for the maximisation test cannot be standardised. Suitable concentrations were established in preliminary tests. The selected concentration of the test substance depends on the individual phases of the study.
- Positive control substance(s):
- not specified
Results and discussion
In vivo (non-LLNA)
Resultsopen allclose all
- Key result
- Reading:
- 1st reading
- Hours after challenge:
- 48
- Group:
- negative control
- Dose level:
- petrolatum
- No. with + reactions:
- 0
- Total no. in group:
- 5
- Remarks on result:
- no indication of skin sensitisation
- Key result
- Reading:
- 1st reading
- Hours after challenge:
- 48
- Group:
- test chemical
- Dose level:
- beta-naphthol 25% in petrolatum
- No. with + reactions:
- 10
- Total no. in group:
- 10
- Clinical observations:
- erythema-score: 2-4, oedema-score: 1-2, dry or rough skin surface at 4 animals, encrusted skin surface at 1 animal, scabbed skin surface at 2 animals
- Remarks on result:
- positive indication of skin sensitisation
- Key result
- Reading:
- 2nd reading
- Hours after challenge:
- 72
- Group:
- negative control
- Dose level:
- petrolatum
- No. with + reactions:
- 0
- Total no. in group:
- 5
- Remarks on result:
- no indication of skin sensitisation
- Key result
- Reading:
- 2nd reading
- Hours after challenge:
- 72
- Group:
- test chemical
- Dose level:
- beta-Naphthol 25% in petrolatum
- No. with + reactions:
- 10
- Total no. in group:
- 10
- Clinical observations:
- erythema-score: 2-4, oedema-score: 0-2, dry or rough skin surface at 7 animals, encrusted skin surface at 2 animals, indurated skin surface at 1 animal, scabbed skin surface at 4 animals
- Remarks on result:
- positive indication of skin sensitisation
- Group:
- positive control
- Remarks on result:
- not measured/tested
Any other information on results incl. tables
Determination of the primary non-irritant concentration
No signs of irritation ocurred after application of the different test concentrations.
Treatment of the animals with Freund's Adjuvant can lower the threshold value for primary irritation determined in preliminary tests. For this reason, the five animals in the escort group which had been treated with Freund's Adjuvant were treated with 25% beta-Naphthol in petrolatum. As no reactions were observed in these animals, a concentration of 25% beta-Naphthol in petrolatum was chosen for the challenge at day 22.
Tolerance of intradermal injections
The injections of the 5,0, 1,0 and 0,2% preparations caused very slight up to well defined erythema and oedema at the application sites. Due to viscosity it was not possible to inject the whole amount of the 5,0% preparation.
Based on this preliminary test, a 2,0% preparation was selected for the intradermal injections in the main test.
Body weight gains and clinical signs
The treated animals showed no clinical signs of intoxication throughout the study.
The intradermal injections with Freund's Adjuvant (with and without test substance) caused well defined up to moderate erythema and oedema. Additionally, the application sites were indurated, encrusted and scabbed. Beige discolorations were observed in the test group. The application sites treated with the test substance showed very slight erythema and slight oedema. The injections with the vehicle alone caused no signs of irritation.
After the removal of the patch at day 10, erythema, oedema, eschar formation, indurated skin and necrosis were observed at the sites previously treated with Freund's Adjuvant. Additionally the sites treated with Freund's Adjuvant and test substance showed open wounds and white discolorations.
The body weight gains of the treated animals were not impaired.
Challenge treatment
No signs of irritation were observed in the control group 24 and 48 hours after removal of the occlusive bandage.
All animals of the treatment group showed well defined up to severe erythema and very slight up to slight oedema. Additionally, the skin was dry, rough, encrusted, indurated and scabbed.
Applicant's summary and conclusion
- Interpretation of results:
- Category 1 (skin sensitising) based on GHS criteria
- Conclusions:
- Based on the positive results of this GPMT beta-napthol has to be considerd to be a skin sensitizer.
- Executive summary:
Testing for sensitizing properties of beta-Naphthol was performed in female guinea pigs according to the method of Magnusson & Kligman.
Intradermal induction was performed using 2% beta-Naphthol in semi-liquid paraffin. Dermal induction and challenge treatment were carried out with 25% beta-Naphthol in petrolatum.
Under the conditions of the study, all animals of the treatment group showed a positive skin response after the challenge procedure.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
