4-[(2,5-dichlorophenyl)azo]-3-hydroxy-N-phenylnaphthalene-2-carboxamide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented study report which meets basic scientific principles.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: FDA guideline (Fed. Reg. Vol. 38, No. 187, p. 27019, 1973)

Deviations:

not specified

GLP compliance:

no

Remarks:

GLP was not compulsory at the time the study was conducted

Test material

Test material information

Constituent 1

Reference substance name:

4-[(2,5-dichlorophenyl)azo]-3-hydroxy-N-phenylnaphthalene-2-carboxamide

EC Number:

227-930-1

EC Name:

4-[(2,5-dichlorophenyl)azo]-3-hydroxy-N-phenylnaphthalene-2-carboxamide

Cas Number:

6041-94-7

Molecular formula:

C23H15Cl2N3O2

IUPAC Name:

4-[(2,5-dichlorophenyl)diazenyl]-3-hydroxy-N-phenyl-2-naphthamide

Test material form:

solid: nanoform, no surface treatment

Details on test material:

Name of test material (as cited in study report): Permanentrot FRR CM 79883
Analytical purity: technically pure.

Test animals

Species:

rabbit

Strain:

Himalayan

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Housing: individually
- Weight at study initiation: 1.5-2.0 kg
- Diet: mixed feed ERKA 8300 (Robert Koch, Hamm), ad libitum
- Water: tap water, ad libitum

Test system

Type of coverage:

occlusive

Preparation of test site:

other: clipped intact and clipped scarified

Vehicle:

other: seasame oil or undiluted

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.5 ml of 10 % dilution and 500 mg of undiluted substance

Duration of treatment / exposure:

24 h

Observation period:

48 h after end of exposure

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: 2.5 x 2.5 cm gauze patch
- Type of wrap if used: PVC foil, elastic bandage

REMOVAL OF TEST SUBSTANCE
- Time after start of exposure: 24 h

SCORING SYSTEM: described in § 1500.41 in Fed. Reg. 38, No. 187, 27.09.1973, p.27019, in accordance with OECD TG 404.
Scores were assessed 24, 48 and 72 h after start of exposure, which lasted for 24 h. For classification, the readings are stated here as immediately, 24 and 48 h after end of exposure.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: #1, #2, #3, #4, #5, #6

Time point:

24/48 h

Score:

ca. 0

Max. score:

4

Reversibility:

other: reversibility not relevant since no effect

Remarks on result:

other: clipped intact and clipped scarified

Results 2

Irritation parameter:

edema score

Basis:

animal: #1, #2, #3, #4, #5, #6

Time point:

24/48 h

Score:

ca. 0

Max. score:

4

Reversibility:

other: reversibility not relevant since no effect

Remarks on result:

other: clipped intact and clipped scarified

Irritant / corrosive response data:

None of the animals showed oedema or erythema at the intact or scarified skin at any time point (immediately, 24 and 48 hours after end of exposure)

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material is not irritating to skin under these test conditions.
This conclusion is legitimate even though the applied testing regime differs from today's standard methods. Since the test conditions were more stringent than required by OECD TG 404 (i.e. 24 h treatment, occlusive coverage, and scarified skin instead of 4 h treatment, semi-occlusive coverage, and intact skin) the test results are considered adequate to fulfill the endpoint requirements.

Executive summary:

The test material was tested for skin irritancy according to FDA guidelines. Both intact and scarified skin sites of six rabbits were exposed to 0.5 g test substance or 0.5 mL of a dilution (10 % in sesame oil) for 24 h under occlusive conditions and the skin responses were watched for 48 hours after end of exposure. No erythema or edema were seen at any time point (score 0). The test item is not irritating under these test conditions.