Isobutyric acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11.10.1983 - 25.10.1983

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1981

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Valeric acid

EC Number:

203-677-2

EC Name:

Valeric acid

Cas Number:

109-52-4

Molecular formula:

C5H10O2

IUPAC Name:

valeric acid

Details on test material:

- Name of test material (as cited in study report): n-Valeriansäure
- Physical state: colorless liquid
- Analytical purity: 99,2 %
- Lot/batch No.: RM 132465
- Expiration date of the lot/batch: 08.09.1983
- Stability under test conditions: no data
- Storage condition of test material: under darkness, 2 °C

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hoechst AG
- Weight at study initiation: 3.4 - 4.2 kg
- Housing: individually in cages, in air-conditioned rooms
- Diet (e.g. ad libitum): Altrumin 2123 rabbit diet, ad libidum
- Water (e.g. ad libitum): deionized and chlorinated water, ad libidum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/- 2
- Humidity (%): 55 +/- 10
- Photoperiod (hrs dark / hrs light): 12/12

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 on a 2.5 x 2.5 cm patch

Duration of treatment / exposure:

60 minutes

Observation period:

0.5-1, 24, 48, 72 hrs after removal of the patch and at day 7 and 14

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 2,5 x 2,5 cm
- Type of wrap if used: special wound healing patches, Fa. Baiersdorf AG, Hamburg, covered and fixed with a semiocclusive bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): removal of test substance without washing as far as possible
- Time after start of exposure: 60 minutes

SCORING SYSTEM: according to Draize

Results and discussion

In vivo

Results

Remarks on result:

other: scoring was impeded due severe rigidification, bulging and discoloration of the exposed area

Any other information on results incl. tables

One hour after removal of the patch, the treated skin of the test animals was green-brown discolored. In the course of observation period the treated skin surface hardened. It became dry and brittle, bulged and changed color via dark red to yellowish brown. After 14 days, severe skin effects were still present. One animal showed peeling of large skin areas, combined with a deep skin lesion and beginning scaring. The skin of one animal was sclerotic and bulged, and the skin of the third animal peeled in large scales.

 

 

Scoring for erythema and edema (maximum score = 4)

 

Erythema

Edema

1 h

24 h

48 h

72 h

7 d

14 d

1 h

24 h

48 h

72 h

7 d

14 d

Rabbit 1

*

*

*

*

*

*

3

1

0

0

*

*

Rabbit 2

2

2

2

2

*

0

2

2

2

1

*

0

Rabbit 3

*

*

*

*

*

*

2

2

1

1

*

*

 

* scoring not possible due to severe hardening, bulging and discoloration

Applicant's summary and conclusion

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Remarks:

Migrated information R 34 Criteria used for interpretation of results: EU

Conclusions:

Classification: corrosive (causes burns)

Executive summary:

In a valid GLP OECD 404 study, 3 rabbits were exposed dermally to single doses of 0.5 ml of undiluted valeric acid for a one-hour period. Skin reactions were scored according to the guideline and were observed for 14 days.

Valeric acid was corrosive to the rabbit's skin after a one-hour contact period, as evidenced by severe skin lesions and scar formation which persisted until teh end of the 14 -days observation period (Hoechst AG, 1983).