2-(3,5-dimethylhex-3-en-2-yloxy)-2-methylpropyl cyclopropanecarboxylate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 June 2008 to 23 June 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

According to the OECD Guideline 404 and in compliance with GLP practices.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Version / remarks:

August 1998

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

Adopted April 24, 2002

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

April 29, 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss legislation on Good Laboratory Practice (signed in September 04, 2008)

Test material

Test material information

Constituent 1

Reference substance name:

2-{[(2R)-3,5-dimethylhex-3-en-2-yl]oxy}-2-methylpropyl cyclopropanecarboxylate; 2-{[(2S)-3,5-dimethylhex-3-en-2-yl]oxy}-2-methylpropyl cyclopropanecarboxylate

EC Number:

700-118-9

Cas Number:

676532-44-8

Molecular formula:

C16H28O3

IUPAC Name:

2-{[(2R)-3,5-dimethylhex-3-en-2-yl]oxy}-2-methylpropyl cyclopropanecarboxylate; 2-{[(2S)-3,5-dimethylhex-3-en-2-yl]oxy}-2-methylpropyl cyclopropanecarboxylate

Test material form:

liquid

Details on test material:

- Description: Colourless liquid
- Formula: C16H28O3
- Molecular weight: 268,4 g/mol

Test animals

Species:

rabbit

Strain:

New Zealand White

Remarks:

Young Adult New Zealand White Rabbit, SPF

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Netherlands BV, Kreuzelweg 53, NL-5961 NM Horst / The Netherlands Postbus 6174
- Age at study initiation: 12 weeks (male); 16-20 weeks (females)
- Weight at study initiation: 2.3, 2,4 and 2,8 kg
- Housing: Individually in stainless steel cages equipped with feed hoppers, drinking water bowls, with autoclaved wood (RCC Ltd, Füllinsdorf) and haysticks 4642 for gnawing.
- Diet (e.g. ad libitum): Pelleted standard Provimi Kliba 3418 rabbit maintenance diet ad libitum (batch nos. 03/08 and 19/08) provided by Provimi Kliba AG, CH-4303 Kaiseraugst.
- Water (e.g. ad libitum): Community tap water from Füllinsdorf, ad libitum.
- Acclimation period: 7 days under laboratory conditions after health examination.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23°C
- Humidity (%): 30-70%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12
- Music was played during the light cycle.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL measured with a syringe and applied undiluted as it was delivered by the sponsor.

Duration of treatment / exposure:

4 hours

Observation period:

Until 7 days after the removal of the dressing, gauze patch and test article.

Number of animals:

1 male and 2 females

Details on study design:

TEST SITE
- Area of exposure: left flank, approximately 100 cm² (10 cm x 10 cm)
- Type of wrap if used: test substance was applied to the intact skin using a surgical gauze patch (ca. 2.5 x 2.5 cm) covered with a semi-occlusive dressing. The dressing was wrapped around the abdomen and anchored with tape.

REMOVAL OF TEST SUBSTANCE
- Washing: The dressing was removed and the skin was flushed with lukewarm tap water to clean the application site so that any reactions (erythema) were clearly visible at that time.
- Time after start of exposure: 4h

OBSERVATION TIME POINTS
- Viability/Mortality and clinical signs: Dai!y from delivery of the animals to the termination of test.
- Body weights: At start of acclimatization, on the day of application and at termination of observation.
- Clinical signs: Daily from acclimatization of the animals to the termination of test.
- Skin reaction: approx 1, 24, 48, 72 hours, as well as 7 days after exposure (removal of the dressing, gauze patch and test item).

SCORING SYSTEM:
Erythema and eschar formation
No erythema: 0
Very slight erythem: 1
Well-defined erythema:2
Moderate to severe erythema: 3
Severe erythema to slight eschar formation: 4

Oedema formation
No oedema:0
Very slight oedema: 1
Slight oedema:2
Moderate oedema:3
Severe oedema:4

The mean score was calculated across 3 scoring times (24, 48 and 72 hours after patch removal) for each animal for erythema/eschar gardes and for oedema grades, separately. An animal is positive when the mean score is 2 or greater. The test is positive for irritation when at least 2 animals are positive for the same endpoint (erythema/eschar or oedema).

All rabits were sacrificed by an intravenous injection of Pentobarbitone into the ear vein at a dose of at least 1 mL/kg bw and discarded.
No necrospy was performed on the animals sacrificed at termination of observation.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

probability of weak irritation

Results 3

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

probability of weak irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

probability of mild irritation

Irritant / corrosive response data:

The mean score was calculated across 3 scoring times (24, 48 and 72 hours after patch removal) for each animal for erythema/eschar grades and for edema grades, separately. The mean erythema/eschar score of the three animals was 1.00, 0.33 and 0.33, respectively and the mean edema score was 0.00 for each of the three animals.

A very slight erythema was observed in all animals 1 hour after test item exposure and persisted up to the 24- and 72-hour reading, respectively.

Other effects:

No abnormal findings were observed on the treated skin of any animal 48 hours and 7 days after treatment, respectively.
No staining produced by the test item of the treated skin was observed.
Neither alterations of the treated skin were observed nor were corrosive effects evident on the skin.
The body weights of all rabbits were considered to be within the normal range of variability.

Any other information on results incl. tables

Individual findings:

Evaluation interval*	Rabbit No.	Sex	Erythema	Oedema
1 hour	66	M	1	0
	67		1	0
	68	F	1	0
24h	66	M	1	0
	67	F	1	0
	68	F	1	0
48h	66	M	1	0
	67	F	0	0
	68	F	0	0
72h	66	M	1	0
	67	F	0	0
	68	F	0	0
7 days	66	M	0	0
	67	F	0	0
	68	F	0	0

*Examinations were performed at the specified times after removal of the dressing.

 

Mean score at 24, 48 and 72h after a 4 hours exposure

 

Animal number	Sex	Erythema	N	Oedema	N
66	M	1.00	3	0.00	3
67	F	0.33	3	0.00	3
68	F	0.33	3	0.00	3

N= number of available data points.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions, test substance is not classified as irritating to skin according to the criteria of the Annex I of the Regulation EC No. 1272/2008 (CLP) and to the GHS.

Executive summary:

In a dermal irritation study performed according to the OECD Guideline No. 404, and in compliance with GLP, 0.5 mL of test material was applied on the clipped skin of the dorsal flank area of 1 male and 2 females New Zealand rabbits. Test sites were covered with a semi-occlusive dressing for 4 hours, followed by several observations at approximately 1, 24, 48 and 72 hours and 7 days after removal of dressing, gauze patch and test substance.

The observed skin irritation consisted of a very slight erythema observed in all animals 1 hour after test item exposure and persisted up to the 24- and 72-hour reading, respectively. All skin reactions were clear within 7 days after treatment.

No abnormal findings were observed on the treated skin of any animal 48 hours and 7 days after treatment, respectively. No staining produced by the test item of the treated skin was observed. Neither alterations of the treated skin were observed nor were corrosive effects evident on the skin. The body weights of all rabbits were considered to be within the normal range of variability.

The mean erythema/eschar score of the three animals was 1.00, 0.33 and 0.33, respectively and the mean oedema score was 0.00 for each of the three animals.

Under the test conditions, test substance is not classified as irritating to skin according to the criteria of the Annex I of the Regulation EC No. 1272/2008 (CLP) and to the GHS. This study is considered as acceptable and satisfies the requirement for skin irritation endpoint.