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Toxicological information

Skin irritation / corrosion

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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 guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
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

Constituent 1
Chemical structure
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

Resultsopen allclose all
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
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
Irritation parameter:
edema score
Basis:
animal: #1, #3
Time point:
other: 24 - 72 h
Score:
0
Max. score:
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