Isovaleric acid

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:

other: Comparable to guideline studies

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Isovaleric acid

EC Number:

207-975-3

EC Name:

Isovaleric acid

Cas Number:

503-74-2

Molecular formula:

C5H10O2

IUPAC Name:

3-methylbutanoic acid

Details on test material:

- Name of test material (as cited in study report): Isovaleriansäure; substance No. 77/520

Test animals

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

no data

Test system

Type of coverage:

not specified

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not required

Duration of treatment / exposure:

3 minutes and 1 hour

Observation period:

8 days

Number of animals:

2 (1hr) and 4 (3 min exposure)

Details on study design:

TEST SITE
- Area of exposure:
- % coverage:
- Type of wrap if used:

REMOVAL OF TEST SUBSTANCE
- Washing (if done):
- Time after start of exposure:

SCORING SYSTEM: BASF; similar to the table of Draize contained in the OECD test guideline

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Remarks:

skin contact: 1hr

Basis:

mean

Time point:

other: 1 hr

Score:

2

Max. score:

4

Remarks on result:

other: Contact period 1 hour in this and following lines.See also section "Any other information on results incl. tables" below.

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: day 1

Score:

3

Max. score:

4

Remarks on result:

other: necrosis in one animal

Results 3

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: day 2

Score:

4

Max. score:

4

Reversibility:

not reversible

Remarks on result:

other: necrosis in both animals

Results 4

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: day 8

Max. score:

4

Reversibility:

not reversible

Remarks on result:

other: necrosis in both animals; scoring of skin reaction not possible

Any other information on results incl. tables

Table 1: skin reactions following a 1-hour exposure. Findings were confirmed by pathologist.

animal	1 hour		Day 1		Day 2		Day 8
	erythema	edema	erythema	edema	erythema	edema	erythema	edema
1	2ext	2ext	4 N	2ext	4 N	2ext	N d	2ext
2	2ext	2ext	2ext N	2ext	4 N	2ext	N d	2ext

 

Table 2: skin reactions following a 3-minute exposure. Findings were confirmed by pathologist.

animal	1 hour		Day 1		Day 2		Day 8
	erythema	edema	erythema	edema	erythema	edema	erythema	edema
1	2ext	2ext	4 N	2ext	4 N	2ext	4 N	2ext
2	2	sup	2ext N	2	2ext N	2ext	Sup N	1
3	1ext	sup	4 N	2ext	4 N	2ext	4 N	2
4	2ext	sup	2ext	2ext	2ext	3ext	2	2

Legend:
grading 1, 2, 3, 4: according to table in OECD 404 (1992)
ext = exteing beyond area of exposure
N = necrosis; N d = deep, entire skin (= full thickness)

Sup = superficial

Applicant's summary and conclusion

Interpretation of results:

corrosive

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Following a 1- hour exposure period isovaleric acid caused full thickness necrosis of the rabbit's skin. Classification (skin corrosion, Cat 1B) is required.

Executive summary:

Isovaleric acid caused irreversible skin reactions and necrosis of the rabbit's skin following a 1-hour skin contact period. Skin contact for 3 minutes caused also necroses, but these were seen one day after the treatment. The study was equivalent to OECD 404 (adopted 1992); (BASF, 1980).

The study is considered to be valid for assessment. According to the regulation EC/1272/2008 isovaleric acid was corrosive to the skin and requires Cat 1B classification.