Ethyl 2-cyclohexylpropionate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 5 November 1991 to 16 November 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to the method B.4 Part B and it is GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl 2-cyclohexylpropionate

EC Number:

412-280-5

EC Name:

Ethyl 2-cyclohexylpropionate

Cas Number:

2511-00-4

Molecular formula:

C11H20O2

IUPAC Name:

ethyl 2-cyclohexylpropanoate

Details on test material:

- Physical state: clear liquid
- Storage condition of test material: 4ºC in the dark

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Froxfield (U.K) Ltd., Petersfield, Hampshire, England
- Age at study initiation: 13/15 weeks
- Weight at study initiation: 2.6-3.0 kg
- Housing: individually in metal cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19
- Humidity (%): 30-70
- Air changes (per hr): 19
- Photoperiod (hrs dark / hrs light): 12-12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.5 mL amount of the test substance

Duration of treatment / exposure:

Examination of the treated skin was made on Day 1 (approximately 30 minutes after removal of the dressings) and on Days 2, 3 and 4 (equivalent to 24 and 48 and 72 after exposure). additional observation were made on Days 5 to 12.

Observation period:

12 days

Number of animals:

Three healthy adults

Details on study design:

TEST SITE
- Area of exposure: 25mm x 25mm

REMOVAL OF TEST SUBSTANCE
- Washing (if done): with warm water to remove any residual test substance

SCORING SYSTEM:
Local dermal irritation was assessed using the prescribed numerical system:

Erythema and eschar formation:
No erythema: 0
Very slight erythema (barely perceptible): 1
Well-defined erythema: 2
Moderate to severe erythema: 3
Severe erythema (beet redness) to slight eschar formation (injuries in depth): 4

Oedema formation:
No oedema: 0
Very slight oedema (barely perceptible): 1
Slight oedema (edges of area well-defined by definite raising): 2
Moderate oedema (raised approximately 1 millimetre): 3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure): 4

Any other lesion not covered by this scoring system, was described.

Results and discussion

In vivo

Irritant / corrosive response data:

CLINICAL SIGNS
There were no signs of toxicity or ill health in any rabbit during the obervation period.
DERMAL RESPONSES
The numerical values given to the dermal reactions elicited by the test substance are in the Table 1. Very slight erythema with very slight to slight oedema was observed in all three animals, Welldefined erythema was seen in one animal on Day 3 only. Desquamation of the stratum corneum (sloughing) was seen in all three animals, in two from Day 7-11 and in one on Days 10 and 11 only.

Any other information on results incl. tables

Table 1: Dermal reactions observed after application of the test substance

Rabbit number and sex	E= Erythema O= Oedema	Day
		1*	2	3	4	5	6	7	8	9	10	11	12
1912 Female	E	1	1	1	1	1	1	1	1	1	1A	0A	0
	O	1	2	1	1	0	0	1	1	1	0	0	0
1913 Female	E	1	1	1	1	1	1	1A	1A	0A	0A	0A	0
	O	1	1	1	1	1	0	1	1	0	0	0	0
1914 Female	E	1	1	2	1	1	1	1A	0A	0A	0A	0A	0
	O	1	2	2	1	1	1	1	0	0	0	0	0

A Sloughing of epidermis

*Approximately 30 minutes after removal of the dressing

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

A single semi-occlusive application of the test substance to intact rabbit skin for four hours elicited slight to well-defined dermal reactions. All reactions had solved by Day 12.

Executive summary:

A study was performed to assess the skin irritation potential of the test substance to the rabbit. The method followed was that described in the method B.4 Part B. Three rabbits were each administered a single dermal dose of 0.5mL of the test substance and observed for a maximim of 12 days. A single semi-occlusive application of the test substance to intact rabbit skin for four hours elicited slight to well-defined dermal reactions. All reactions had resolved by Day 12. The test substance does not require labelling with the risk phrase R38 "Irritating to skin" in accordance with EEC Council Direcitve 79/831/EEC, Annex VI, Part II (D) as described in Commission Directive 91/325/EEC.