3,5,5-trimethylhexanal

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Read across is applied to a structural analogue

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1964

Report date:

1964

Materials and methods

Principles of method if other than guideline:

Skin irritation was tested using an internal standard method (BASF test). White Vienna rabbits were used. Usually, 2 animals were treated for 1, 5 and 15 minutes and 2 other animals for 20 hours using occlusive conditions. An application site of 2.5 X 2.5 cm was covered with the liquid or powdered and moistened test substance.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-ethylhexanal

EC Number:

204-596-5

EC Name:

2-ethylhexanal

Cas Number:

123-05-7

Molecular formula:

C8H16O

IUPAC Name:

2-ethylhexanal

Details on test material:

- Name of test material (as cited in study report): Äthylhexanal (German)
- Physical state: liquid
- Analytical purity: ca. 98 %
- Expiration date of the lot/batch: not reported
- Stability under test conditions: not reported
- Storage condition of test material: not reported

Test animals

Species:

rabbit

Strain:

Vienna White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Breeder
- Weight at study initiation: 2.36 kg and 2.00 kg
- Weight at study conclusion: 2.34 kg and 2.11 kg

Test system

Type of coverage:

occlusive

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): prosumably 2 ml

Duration of treatment / exposure:

Experiment 1: 1, 5, or 15 minutes
Experiment 2: 20 h

Observation period:

8 days

Number of animals:

2

Details on study design:

TEST SITE
- Area of exposure: An application site of 2.5 X 2.5 cm was covered with the liquid (37°C; prosumably 2 ml)
REMOVAL OF TEST SUBSTANCE
- Washing (if done):
Experiment 1: washing was done for in the 1 min, 5 min and 15 min test directly after exposure. Lutrol 50 % (mild detergent) was used.
Experiment 2: No washing was done after the 20 h treatment.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

20 h exposure

Time point:

other: 24 - 48- 72 h

Score:

2.6

Max. score:

3

Reversibility:

fully reversible within: 8 d

Remarks on result:

other: scale formation in both animals, see table for further details

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

20 h exposure

Time point:

other: 24 - 48 - 72 h

Score:

2.4

Max. score:

3

Reversibility:

fully reversible within: 8 d

Remarks on result:

other: see table for further details

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

15 min exposure

Time point:

other: 24 - 48 - 72 h

Score:

2.83

Max. score:

3

Reversibility:

not fully reversible within: 8 d

Remarks on result:

other: Erythema remained in one animal, see table for further details

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

15 min exposure

Time point:

other: 24 - 48 - 72 h

Score:

1.83

Max. score:

3

Reversibility:

fully reversible within: 8 d

Remarks on result:

other: see table for further details

Any other information on results incl. tables

Since irritation data from a 4 h skin exposition model are recommended, results for the available 20 h and the 15 min exposition served as approximation. Descriptive scores of the raw data have been converted to Draize numerical scores. If necroses were reported, erythema scores were given for the surrounding area.

Exposition:	20 h
Animal	Reading	Erythema	Edema	Comment
1	24 h	2	3	yellow-red, surrounding area ca. 2-5 cm width
2	24 h	3	3	yellow brown, lobule-size with punctual hemorrhage, surrounding area 2-5 cm width
1	48 h	3	3	brown, overlapping
2	48 h	2	0	yellow, overlapping, application site brown
1	72 h	3	3	light brown, necrosis, surrounding area ca. 5 cm width
2	72 h			yellow, overlapping, application site brown
1	4 d	2	3	light brown, necrosis, surrounding area ca. 5 cm width
2	4 d	2	0	superficial yellow brown, necrosis, starting scale formation
1	7 d	0	0	light and smooth crust formation, widely overlapping, light scaling
2	7 d	0	0	yellow brown, necrosis, scaling
1	8 d	0	0	light and smooth crust formation detaching, widely overlapping, light scale formation
2	8 d	0	0	yellow brown, necrosis, scaling
mean	24-72 h	2,60	2,40
Exposition:	15 min
Animal	Reading	Erythema	Edema	Comment
1	24 h	3	2	overlapping with yellow areas
2	24 h	3	2	overlapping
1	48 h	3	2	overlapping
2	48 h	2	0	light overlapping
1	72 h	3	3	overlapping, parchmenty
2	72 h	3	2	overlapping
1	4 d	2	0	overlapping, parchmenty
2	4 d	2	2	starting scale formation
1	7 d	1	0	rough scaling
2	7 d	0	0	scaling
1	8 d	1	0	rough scaling
2	8 d	0	0	scaling
mean	24-72 h	2,83	1,83

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Executive summary:

This supporting study meets scientific standards with acceptable restrictions (limited documentation, e.g. no details about test substance or applied amount of test substance). Skin irritation was tested using an internal standard method (BASF test). White Vienna rabbits were used. Usually, 2 animals were treated for 1, 5 and 15 minutes and 2 other animals for 20 hours using occlusive conditions. An application site of 2.5 X 2.5 cm was covered with the test substance.

The test substance induced marked Erythema and edema formation even after a 1 min exposure. After 20 h exposure and 8 days observation edemas are questionable while marked scale formation was reported. Scale formation began already after 20 h exposure and 24 h observation. Scale formation is a hint for skin regeneration after skin corrosion.

Substance is irritant to the skin.