3-methyl-1-phenyl-5-pyrazolone

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The identity of the test substance was not sufficiently documented. Only a summary test report was available, there was no raw data. However, the study was conducted under FDA test protocols. Appropriate dose level was used. The scoring system deviated slighty from the current OECD protocol. Control analysis was performed. Restriction for reliability was due to the age of the study (1980).

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:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

The identity of the test substance was not sufficiently documented. Only a summary test report was available, there was no raw data. However, the study was conducted under FDA test protocols. Appropriate dose level was used. The scoring system deviated slighty from the current OECD protocol. Control analysis was performed. Restriction for reliability was due to the age of the study (1980).

Deviations:

yes

Remarks:

See text above in "Version/remarks" section

Principles of method if other than guideline:

Before the start of the study the hair in the dorsal region of the body of 6 rabbits was remoced with an electric clipper over an area of about 3x 6 cm. One half of the clipped skin was in addition scarified with a scarificator. Each animal was treated with 500 mg of 1-Phenyl-3-methyl-5-pyrazolon pasted with 0.35 ml physiologic saline solution. The substance was evenly distributed over the whole surface of 2.3 x 2.5 cm cellulose patch on a piece of surgical plaster (Hansamed(R)). The plaster was fixed to the prepared skin area and covered with a indifferent, impermeable polyethylene film (6-8cm wide). Finally the animals body was fixed with an elastic bandage. The exposure period was 4 hours. A first examination took place immediately after removal of the patches. Further examination tool place after 48 and 72 hours post application.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

3-methyl-1-phenyl-5-pyrazolone

EC Number:

201-891-0

EC Name:

3-methyl-1-phenyl-5-pyrazolone

Cas Number:

89-25-8

Molecular formula:

C10H10N2O

IUPAC Name:

5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one

Test animals

Species:

rabbit

Strain:

Himalayan

Remarks:

Albino-Himalayan ; Hoe:HIML (SPFWiga)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: from the test facility laboratory
- Age at study initiation: not specified
- Weight at study initiation:1.7 to 2.1 kg
- Housing: animals were housed in single cages
- Diet (e.g. ad libitum): ERKA 8300 (Futtermittelwerk Tobert Koch oHG, Hamm/Wastfalen) ad libitum
- Water (e.g. ad libitum): water, ad libitum
- Acclimation period: not specified

ENVIRONMENTAL CONDITIONS
No information

IN-LIFE DATES: Not specified

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 500 mg

VEHICLE
Vehicle was not used

NEGATIVE CONTROL
Not specified

POSITIVE CONTROL
Not specified

Duration of treatment / exposure:

4 hours

Observation period:

At the patch removal, 48 and 72 hours post application

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: dorsal region of the body
- % coverage: not specified
- Type of wrap if used: piece of surgical plaster (Hansamed (R))

REMOVAL OF TEST SUBSTANCE
Not specified

OBSERVATION TIME POINTS
(indicate if minutes, hours or days)
At the removal, 48 and 72 hours

SCORING SYSTEM:
- Method of calculation:
Erythema and eschar formation
No erythema 0
Very slight erythema (barely perceptible) 1
Well defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) to eschar formation (injuries in depth) preventing grading of erythema 4

Edema
No edema 0
Very slight edema (barely perceptible) 1
Slight edema (edges of area well defined by definite raising 2
Moderate edema (raised approximately 1mm) 3
Severe edema (raised more than 1mm and extending beyond the area of exposure) 4

The scores for erythema and eschar formation as well as for edema formation obtained in each rabbit on intact or scarified skin after 24 or 72 hours was added to given the primary irritation score. The sum of all values was divided by number of animals and a factor of 4. The classification was done according to the following evaluation scale.
0-0.5 non irritationg
0.6-3.0 slighty irritant
3.1-5.0 moderately irritant
5.1-8.0 severely irritant

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

24/48/72 h

Score:

1.5

Reversibility:

not specified

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Remarks on result:

no indication of irritation

Remarks:

edema and erythema scpre per animal were not available. Only primary dermal irritation index PDII was available in the report

Results 3

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Remarks on result:

no indication of irritation

Remarks:

edema and erythema scpre per animal were not available. Only primary dermal irritation index PDII was available in the report

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

After application of the substance (pasty form) an irritation index score of 1.5 was determined. Due to classification according to the FDA guideline mentionned in the report, the substance was therefore to be described as slighty irritant. Under CLP regulation, the obtained score of 1.5 did not led to a EU-CLP classification. Hence, the test article was not classified for Skin Irritation.

Executive summary:

The study was conducted to evluate skin irritation potential of the test article when applied on rabbit skin.

Before the start of the study the hair in the dorsal region of the body of 6 rabbits was remoced with an electric clipper over an area of about 3x 6  cm. One half of the clipped skin was in addition scarified with a scarificator. Each animal was treated with 500 mg of 1-Phenyl-3-methyl-5-pyrazolon pasted with 0.35 ml physiologic saline solution. The substance was evenly distributed over the whole surface of 2.3 x 2.5 cm cellulose patch on a piece of surgical plaster (Hansamed(R)). The plaster was fixed to the prepared skin area and covered with a indifferent, impermeable polyethylene film (6-8cm wide). Finally the animals body was fixed with an elastic bandage. The exposure period was 4 hours. A first examination took place immediately after removal of the patches. Further examination tool place after 48 and 72 hours post application.

After application of the substance (pasty form) an irritation index score of 1.5 was determined. Due to classification according to the FDA guideline mentionned in the report, the substance was therefore to be described as slighty irritant. under CLP regulation, the obtained score of1.5 did not led to a EU-CLP classification. Hence, the test article was not classified for Skin Irritation.