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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1980
Report Date:
1980

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
other: Consumer Product Safety Commision, USA; Code of Federal Regulation, Title 16, Section 1500.41
Principles of method if other than guideline:
The method used is similar to OECD test guideline 404 (Acute Dermal Irritation/Corrosion) with some deviations (exposure period is 24 h, the solid test substance was suspended (actually 10% naphthalene suspension in 0.5% carboxymethyl cellulose), occlusive wrapping, test substance is applied on intact and on scarified skin, scores are taken immediately after removal of the patches and 48 h thereafter).
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 104.111; Naphthalin, rein, 79.6°, granuliert
- no further information on test substance
- Fraction in Naphthalene oil: >= 35 %

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Scheele, Büderich, Germany
- no further information

Test system

Type of coverage:
occlusive
Preparation of test site:
other: One side of the rabbit's back was shaved, the other was shaved and scarified.
Vehicle:
other: CMC (0.5 % in water)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g
- Concentration (if solution): 10 %

VEHICLE
- Amount(s) applied (volume or weight with unit): carboxymethylcellulose (CMC)
Duration of treatment / exposure:
24 h
Observation period:
48 h
Number of animals:
6
Details on study design:
TEST SITE
- Area of exposure: ca 2,5 x 2.5 cm
- Type of wrap if used: no data (but occlusive wrapping)

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no data
- Time after start of exposure: 24 h

SCORING SYSTEM: according to Draize (ETAD recommendation)

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 0 h and 48 h after removal of patch
Score:
1.75
Max. score:
8
Reversibility:
not fully reversible within: 48 h
Remarks on result:
other: Score includes readings for intact and for scarified skin.
Irritation parameter:
erythema score
Basis:
mean
Time point:
other: 0 h and 48 h after removal of patch
Score:
1.083
Max. score:
4
Reversibility:
not fully reversible within: 48 h
Remarks on result:
other: observation period only 48 h after patch removal.
Irritation parameter:
edema score
Basis:
mean
Time point:
other: 0 h and 48 h after removal of patch
Score:
0.75
Max. score:
4
Reversibility:
not fully reversible within: 48 h
Remarks on result:
other: observation period only 48 h after patch removal

Any other information on results incl. tables

Irritation scores for naphthalene according to Draize in a primary irritation test (times for readings are after removal of the patch):

 

 

Erythema

Edema

0 h

48 h

0 h

48 h

Rabbit 1

2

1

2

1

Rabbit 2

1

1

1

1

Rabbit 3

2

1

1

0

Rabbit 4

1

0

0

0

Rabbit 5

1

2

1

1

Rabbit 6

1

0

1

0

mean

1.333

0.833

1.0

0.5

mean

1.083

0.75

 

 

The mean score for erythema and edema was consistently below 2 in individual animals.

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
After occlusive dermal administration of 0.5 g naphthalene on the clipped skin of six rabbit for 24 h, slight erythema and edema were observed (scores 2 or lower). Observation times were immediately and 48 h after removal of the patch. At the 48 h reading, skin reactions were diminished to some extent but had not completely subsided. Due to the moderate scores observed, it is concluded that irritation effects will have disappeared at the end of the regular 2 weeks observation period. Criteria for classification as irritating according to EU regulations have not been exceeded.