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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:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study with acceptable restrictions (limited documentation, low dosing), acceptable for assessment

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Unnamed
Year:
1985
Reference Type:
review article or handbook
Title:
Unnamed
Year:
2003

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
as of 12 May 1981
Deviations:
yes
Remarks:
non-occlusive challenge treatment; FCA-water mixture not applied
Principles of method if other than guideline:
Guinea pig maximization test reported by Magnusson and Kligman 1969:
Comparative study including naphthalene, Naphthol AS [CAS No. 92-77-3], 2-naphthol [CAS No. 135-19-3] and 2-hydroxy-3-naphthoic acid [CAS No. 92-70-6]
GLP compliance:
not specified
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): naphthalene
- Supplier: Katayama Chemical Co., Ltd.
- Molecular formula (if other than submission substance): C10H8
- Molecular weight (if other than submission substance): 128.18
- Substance type: organic
- Physical state: solid
- Analytical purity: no data

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
body weight 300 - 350 g

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
other: paraffin oil and white vaseline (induction) / acetone (challenge)
Concentration / amount:
1 % (i.d induction); 10 % (epicutaneous induction) / 0.1 and 1 % (epicutaneous challenge)
Challengeopen allclose all
Route:
epicutaneous, open
Vehicle:
other: paraffin oil and white vaseline (induction) / acetone (challenge)
Concentration / amount:
1 % (i.d induction); 10 % (epicutaneous induction) / 0.1 and 1 % (epicutaneous challenge)
No. of animals per dose:
12 treated animals each;
12 in the untreated control group (only the vehicle)
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 1 (i.d.); 1 (topical)
- Exposure period: 48 h topical
- Test groups: test substance
- Control group: no data (2-naphthol as surrogate)
- Site: shoulder
- Frequency of applications: day 0 (i.d.); day 7 (topical)
- Duration: 7 + 2 days
- Concentrations: First induction:
50 µL i.d. injected in 1 % of test substance in liquid paraffin
50 µL i.d. injected in 1 % of test substance in Freund´s complete adjuvants (FCA)
(Dose: 500 µg each)
Second induction: after 7 d: topically 10 % of test substance in vaseline (volume: no data) for 48 h (closed patch)

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 21
- Exposure period: 24 h
- Test groups: test substance
- Control group: no data (2-naphthol as surrogate)
- Site: flank
- Concentrations: 0.1 and 1 % in acetone
- Dosage volume: 20 µL/cm2
- Dose: 20 and 200 µg/cm2
- Evaluation (hr after challenge): 24 and 48 h
Challenge controls:
no data
Positive control substance(s):
not specified
Remarks:
No accepted standard mentioned: 2-naphthol proved the responsiveness of the test system.

Results and discussion

Positive control results:
2-Naphthol: 8/8 animals clearly positive

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
0.1 and 1 %
No. with + reactions:
0
Total no. in group:
24
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.1 and 1 %. No with. + reactions: 0.0. Total no. in groups: 24.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
0.1 and 1 %
No. with + reactions:
0
Total no. in group:
24
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.1 and 1 %. No with. + reactions: 0.0. Total no. in groups: 24.0.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Considering the quality of the reporting and the low challenge concentrations of naphthalene used, no firm conclusions can be drawn from this study (ECB 2003).
Executive summary:

In a poorly reported skin sensitisation study based on the guinea pig maximisation method, a 24-hour open application dermal challenge, with 0.1% or 1% naphthalene in acetone, did not produce any sign of a sensitisation reaction in any of the 24 animals. However no information was provided on the use of positive controls, and at the induction stage no signs of naphthalene-induced irritation were reported at the concentrations examined. However, 2-naphthol was also tested and was positive in all 16 animals tested.