5-amino-o-cresol

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1975

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Basic data provided, followed scientific principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1975

Report date:

1975

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: The Code of Federal Regulations 16 CFR 1500.41 (Method of testing primary irritant substances)

Deviations:

yes

Remarks:

only three rabbits were used against six as recommended by guideline

GLP compliance:

no

Remarks:

Pre-GLP

Test material

Test material information

Constituent 1

Reference substance name:

5-amino-o-cresol

EC Number:

220-618-6

EC Name:

5-amino-o-cresol

Cas Number:

2835-95-2

Molecular formula:

C7H9NO

IUPAC Name:

5-amino-2-methylphenol

Constituent 2

Reference substance name:

4-amino-2-hydroxytoluene

IUPAC Name:

4-amino-2-hydroxytoluene

Test material form:

not specified

Details on test material:

- Name of test material: 4-amino-2-hydroxytoluene
- No other information on ‘details of test material’ was provided in the study report.

Test animals

Species:

rabbit

Strain:

other: albino

Details on test animals or test system and environmental conditions:

- No information on the details on ‘test animals and environmental conditions’ were provided in the study report.

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

other: 0.5% aqueous gum tragacanth containing 0.05 % sodium sulphite (pH: 7.0)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.5 mL
- Concentration: 2.5% w/v solution

VEHICLE
- Concentration: 0.5% aqueous gum tragacanth containing 0.05 % sodium sulphite (pH: 7.0)
- Lot/batch no.: Not reported
- Purity: Not reported

Duration of treatment / exposure:

24 hour

Observation period:

24 and 72 hours post exposure period

Number of animals:

3 rabbits

Details on study design:

TEST SITE
- Area of exposure: The test substance was applied on the intact and abraded skin on back of animal, clipped free of hair (shaved).
- Method of treatment: 0.5 mL of dosing solution was applied under square patch, measuring 1 inch by 1 inch. The animals ware immobilized with patches secured in place by adhesive tape.

USE OF RESTRAINERS FOR PREVENTING INGESTION: Yes; During exposure period, the entire trunk of the animal was then wrapped with an impervious material for the 24-hour period of exposure.

REMOVAL OF TEST SUBSTANCE
- Washing : Yes
- Time after start of exposure: 24 hour

SCORING SYSTEM: The skin reaction were graded on the basis of following scale:
- Erythema and eschar reaction
No erythema:.....................................................................................................................................................0
Very slight erythema (barely perceptible): ...................................................................................................1
Well-defined erythema: ...................................................................................................................................2
Moderate to severe erythema: ........................................................................................................................3
Severe erythema (beet redness) to slight eschar formation (injuries in depth):.................................... 4

- Oedema Formation
No oedema: ........................................................................................................................................................0
Very slight oedema (barely perceptible): .......................................................................................................1
Slight oedema (edges of area well-defined by definite raising): ................................................................2
Moderate oedema (raised approximately 1 mm): .........................................................................................3
Severe oedema (raised more than 1 mm and extending beyond area of exposure): .............................4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: erythema and edema score

Basis:

animal: 1, 2 and 3

Time point:

other: 24 and 72 hour

Score:

0

Max. score:

4

Remarks on result:

other: No skin reaction was observed

Results 2

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 7

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

None of the animals showed any observable response to treatment throughout the 72 hour observation period.

Other effects:

Not reported

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

Under 24 hour occlusive contact, a 2.5% aqueous solution of 4-amino-2-hydroxy toluene showed no skin irritating potential in rabbits under the described test conditions.

Although the test procedure did not follow currently accepted guidelines and the purity of the test substance is unknown, the results can be accepted as being indicative of the irritant potential of a 2.5% dilution of the test substance

Executive summary:

The acute skin irritation potential o f4-amino-2-hydroxy toluene was determined following method according to the Code of Federal Regulations 16 CFR 1500.41 (Method of testing primary irritant substances).

0.5 mL of a 2.5% solution of 4-amino-2-hydroxy toluene in aqueous gum tragacanth (0.5%) containing 0.05% sodium sulphite was applied to shaved areas (about 6.45 cm2) of the back of 3 albino rabbits. After 24 hours under occlusive conditions, the test substance was removed. Animals were examined for signs of erythema and oedema 24 and 72 hours post exposure period.

None of the animals showed any observable response to treatment throughout the 72 hours observation period.

Under 24 hour occlusive contact, a 2.5% aqueous solution of 4-amino-2-hydroxy toluene showed no skin irritating potential in rabbits under the described test conditions. Although the test procedure did not follow currently accepted guidelines and the purity of the test substance is unknown, the results can be accepted as being indicative of the irritant potential of a 2.5% dilution of the test substance.