Isobutyraldehyde

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

Pharma Forschung Toxikologie und Pathologie, Hoechst Aktiengesellschaft, 6230 Frankfurt 80

Test material

Test material information

Constituent 1

Reference substance name:

Isobutyraldehyde

EC Number:

201-149-6

EC Name:

Isobutyraldehyde

Cas Number:

78-84-2

Molecular formula:

C4H8O

IUPAC Name:

2-methylpropanal

Details on test material:

- Name of test material (as cited in study report): Isobutanal
- Product No.: IDBY 925
- Physical state: colorless liquid
- Purity ≥ 99% (with up to 0.1% water, 0.2% n-butyraldehyde and 0.3% isobutanoic acid)
- Storage: in the dark at 20°C

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hoechst AG, Kastengrund
- Age at study initiation: 3 – 5 months
- Weight at study initiation: 1.9 – 2.4 kg
- Housing: 1 animal per cage
- Diet: ad libitum Altromin 2123 (standard diet for rabbits), Altromin-GmbH, Lage/Lippe
- Water: demineralized water ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ± 3
- Humidity (%): 50 ± 20
- Air: air-conditioned
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

4 h

Observation period:

The assessments were done 30 - 60 minutes as well as 24, 48 and 72 hours after removal of the patch. Since skin findings were observed after 72 hours, a secondary assessment was done after 7 days.

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 2.5 x 2.5 cm
- Type of wrap if used: band-aid

REMOVAL OF TEST SUBSTANCE
- Washing: lukewarm water
- Time after start of exposure: 4 hours

SCORING SYSTEM: The erythema and eschar formation as well as the edema formation were evaluated numerically.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: 24 - 72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Results 2

Irritation parameter:

erythema score

Basis:

animal: #2, #3

Time point:

other: 24 - 72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 7 days

Results 3

Irritation parameter:

edema score

Basis:

animal: #1, #3

Time point:

other: 24 - 72 h

Score:

0

Max. score:

4

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: 24 - 72 h

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Irritant / corrosive response data:

One hour after removal of the patch no skin irritation was noticed. 24 - 72 hours after removal of the patch the skin showed marginal discernible up to clearly transcribed erythema, one animal showed a very slight edema. After 7 days these findings were reversible. 48 hours - 7 days the skin of 2 animals was scarious and rough.

Applicant's summary and conclusion

Interpretation of results:

not irritating