4-methylpentan-2-one

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented, according to accepted guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

- room temperature was 16 to 22 °C, relative humidity was 40 to 80%, and artificial lighting was 14 hr.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

not specified

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-methylpentan-2-one

EC Number:

203-550-1

EC Name:

4-methylpentan-2-one

Cas Number:

108-10-1

Molecular formula:

C6H12O

IUPAC Name:

4-methylpentan-2-one

Details on test material:

- Name of test material (as cited in study report): methyl iso butyl ketone.
- Physical state: Colourless liquid.
- Analytical purity: 99.5%.
- Lot/batch No.: D215600281.
- Expiration date of the lot/batch: 22 November 1996.
- Stability under test conditions: Not reported.
- Storage condition of test material: Stored at room temperature in the original container.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Ltd., Margate.
- Age at study initiation: 13 to 17 weeks.
- Weight at study initiation: 2.5 to 3.13 kg.
- Housing: Housed individually in floor-pens.
- Diet (e.g. ad libitum): SQC TRB Rabbit Diet 9603 (pelleted) from Harlan Teklad, Bicester, ad libitum.
- Water (e.g. ad libitum):Mains water, ad libitum.
- Acclimation period: At least 7 days.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16 to 22 °C.
- Humidity (%): 40 to 80 %.
- Air changes (per hr): At least 10.
- Photoperiod (hrs dark / hrs light): 10 hrs dark / 14 hrs light.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL.
- Concentration (if solution): Undiluted test substance.

Duration of treatment / exposure:

4 hour, single exposure.

Observation period:

72 hours.

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: Dorsum
- % coverage: Percentage not reported; covered by a dense gauze patch of 30 x 20 mm and this in turn was covered by a larger gauze patch (40 x 40 mm).
- Type of wrap if used: An open weave, elasticated adhesive bandage "Steroban" from Steroplast Ltd., Bredbury.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): The treated skin was swabbed with moist cotton wool after patch removal.
- Time after start of exposure: 4 hours after start of exposure.


SCORING SYSTEM: Inflammatory skin reactions were graded according to the following scheme:

Erythema and eschar formation: Grade
No erythema: 0
Very slight erythema (barely perceptible): 1
Well-defined erythema: 2
Moderate erythema: 3
Severe erythema (beet redness) or eschar formation preventing grading of erythema: 4

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

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no reaction observed

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no reaction observed

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no reaction observed

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Max. score:

4

Reversibility:

other: no reaction observed

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Max. score:

4

Reversibility:

other: no reaction observed

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Max. score:

4

Reversibility:

other: no reaction observed

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No dermal response to treatment was observed in any animals throughout the observation period. See Attached File 1 Table 1 for individual data. See Attached File 1 Table 2 for group mean values for dermal reactions.

Other effects:

There were no signs of toxicity or ill health in any rabbits during the observation period.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Not classified. Criteria used for interpretation of results: other: CLP (EC 1272/2008)

Conclusions:

No irritation reactions or other dermal changes were observed following a single semi-occluded application of methyl iso butyl ketone to intact rabbit skin for 4 hours.

Executive summary:

A skin irritation study on methyl iso butyl ketone has been performed in accordance with OECD Guidelines for the Testing of Chemicals No. 404 and in compliance with GLP (Gardner, 1996).  In this study, 3 New Zealand White rabbits were exposed to 0.5 mL of undiluted methyl iso butyl ketone on the shaved dorsal region under semi-occlusive conditions.  Animals were exposed to the test compound for 4 hours and observations were recorded at 1, 24, 48, and 72 hours after removal of the patch and residual test substance.  Skin reactions were scored according to a prescribed numerical system.  No dermal response to treatment was observed in any animals throughout the observation period. In addition, no signs of toxicity or ill health were observed in any rabbit during the observational period.  Based on the results of this study, methyl iso butyl ketone elicited no dermal irritation to intact rabbit skin. Methyl iso butyl ketone is not classified as a skin irritant according to CLP.