Hexanoic acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Oct - 13 Nov 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

1981

Deviations:

yes

Remarks:

limited data; occlusive dressing

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Hexanoic acid

EC Number:

205-550-7

EC Name:

Hexanoic acid

Cas Number:

142-62-1

Molecular formula:

C6H12O2

IUPAC Name:

hexanoic acid

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: mean weight 3294 g

Test system

Type of coverage:

occlusive

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:

21 days
Reading time points: immediately, 1, 24, 48 and 72 h and 6, 8, 10, 13, 15, 17 and 21 days after patch removal

Number of animals:

5

Details on study design:

TEST SITE
- Area of exposure: dorsal area (3 cm x 3 cm)
The substance was applied on shaved skin and covered with a linen lobule.
- Type of wrap if used: polyethylene foil wrapped with an elastic bandage

REMOVAL OF TEST SUBSTANCE
- Washing: The skin was cleaned of residual test substance.
- Time after start of exposure: 4 h

SCORING SYSTEM: Draize scoring system

Body weights of the rabbits were determined 7, 14 and 21 days after initiation of the study.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: necrosis and scar tissue

Basis:

other: all 5 animals

Time point:

other: 21 days

Reversibility:

not reversible

Remarks on result:

other: scar tissue was observed at the treated sites in all animals at the end of the observation period, indicating irreversible skin damage

Results 2

Irritation parameter:

erythema score

Time point:

24/48/72 h

Remarks on result:

other: scores were not given

Results 3

Irritation parameter:

edema score

Time point:

24/48/72 h

Remarks on result:

other: scores were not given

Irritant / corrosive response data:

Immediately after removal of the dressing, intensive erythema and edema was observed. The edema had disappeared after seven days, the erythema however persisted and passed into a full thickness necrosis.
10 days after initiation of the study eschar started to separate from treated skin. Another 7 days later eschar was completely separated from skin. 21 days after treatment a red scar tissue with single eschar rest had developed. Around the scar tissue, an intensified growth of hair appeared and on the treated skin area, there were just single flocci.
Based on the findings the test material is considered corrosive under the experimental conditions chosen. Corrosive effects are expected even if the study would had been conducted under semiocclusive conditions: As the test material has a very low vapour pressure, evaporating of the test material from the skin through the semiocclusive dressing is rather unlikely.

Other effects:

The body weights of the animals showed normal growth and were upto 3644 g at the end of the study.

Applicant's summary and conclusion

Interpretation of results:

other: classification as Skin Corr. 1C, H314 required according to Regulation (EC) No 1272/2008

Conclusions:

CLP: Skin Corr. 1C, H314