Naphtha (coal), distn. residues

Skin irritation / corrosion

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

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

Test material information

Constituent 1

Reference substance name:

Naphthalene

EC Number:

202-049-5

EC Name:

Naphthalene

Cas Number:

91-20-3

Molecular formula:

C10H8

IUPAC Name:

naphthalene

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 or test system 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

Results

Results 1

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.

Results 2

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.

Results 3

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.