(E)-1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-buten-1-one

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From July 10 to 13, 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

Study performed similarly to US-FHSA guideline. Deviations from standard method : no details on test animals, test on intact and abraded skin, 24 h exposure instead of 4h, occlusive dressing instead of semi-occlusive, observation at 24 and 72 h only (no 48h scoring), no reversibility period although effects have been observed until the end of the study. However, considering the very worst case conditions used in this test (occlusive conditions, no removal of test item reported, abraded skin) and the low scores measured at 72h, a full recovery could be expected after a normal recovery period of 14 day. Therefore this study is considered sufficiently reliable to conclude for classification purposes.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: Section 1500.41 - Hazardous Substances and Articles, Administration and Enforcement Regulations, Federal Register, Vol. 38, No. 187, P. 27019, 27 September 1973.

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

no

Remarks:

pre-GLP

Test material

Test material information

Constituent 1

Reference substance name:

(E)-1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-buten-1-one

EC Number:

246-430-4

EC Name:

(E)-1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-buten-1-one

Cas Number:

24720-09-0

Molecular formula:

C13H20O

IUPAC Name:

1-(2,6,6-trimethylcyclohex-2-en-1-yl)but-2-en-1-one

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): PA 279-7
- Other: Density: Approximately 1 g/mL

Test animals

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

No data

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g
- Tested as supplied

Duration of treatment / exposure:

24 h

Observation period:

24 and 72 h

Number of animals:

6

Details on study design:

TEST SITE (intact & abraded skin)
- Area of exposure: Side of the animal's back (one side abraded skin, the other side remains intact)
- Type of wrap if used: Treated areas were covered with gauze patches and an impervious material was wrapped snugly around the trunk of each animal.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No

SCORING SYSTEM: Draize method.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 2

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 3

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 4

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

animal #4

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 5

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

animal #5

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 6

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

animal #6

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 7

Irritation parameter:

edema score

Remarks:

Intact skin

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 8

Irritation parameter:

edema score

Remarks:

Intact skin

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: no indication of irritation

Remarks:

24/72 h

Results 9

Irritation parameter:

edema score

Remarks:

Intact skin

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

24/72 h

Results 10

Irritation parameter:

edema score

Remarks:

Intact skin

Basis:

animal #4

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 11

Irritation parameter:

edema score

Remarks:

Intact skin

Basis:

animal #5

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 12

Irritation parameter:

edema score

Remarks:

Intact skin

Basis:

animal #6

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 13

Irritation parameter:

erythema score

Remarks:

Abraded skin

Basis:

other: animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 14

Irritation parameter:

erythema score

Remarks:

Abraded skin

Basis:

other: animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: Not applicable

Remarks on result:

other: no indication of irritation

Remarks:

24 and 72 h

Results 15

Irritation parameter:

erythema score

Remarks:

Abraded skin

Basis:

other: animal #3

Time point:

24/48/72 h

Score:

1.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

24 and 48h

Results 16

Irritation parameter:

erythema score

Remarks:

Abraded skin

Basis:

other: animal #4

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 17

Irritation parameter:

erythema score

Remarks:

abraded

Basis:

other: animal #5

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 18

Irritation parameter:

erythema score

Remarks:

abraded

Basis:

other: animal #6

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 19

Irritation parameter:

edema score

Remarks:

abraded

Basis:

other: animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 20

Irritation parameter:

edema score

Remarks:

abraded

Basis:

other: animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 21

Irritation parameter:

edema score

Remarks:

abraded

Basis:

other: animal #3

Time point:

24/48/72 h

Score:

1.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 22

Irritation parameter:

edema score

Remarks:

abraded

Basis:

other: animal #4

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 23

Irritation parameter:

edema score

Remarks:

abraded

Basis:

other: animal #5

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Results 24

Irritation parameter:

edema score

Remarks:

abraded

Basis:

other: animal #6

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

not specified

Remarks on result:

other: no indication of irritation

Remarks:

Time point: 24/72 h (no 48 h scoring)

Irritant / corrosive response data:

- Slight to well defined erythema and slight to moderate oedema were observed under occlusive conditions.
- The average score in the abraded skin is similar to that for the intact skin, both under occlusive conditions.
- Reversibility is not observed at 72 h but the study terminated after 72 h, with no removal of residue (or at least not reported) after the treatment of test item to the skin and thus no observation period after removal of the substance (recovery period). The average scores observed are low and thus a full recovery could be expected after a normal recovery period of 14 day.

Other effects:

No data

Any other information on results incl. tables

Table 7.3.1/1: Mean irritant/corrosive response data for all animals at each observation time up to removal of animals from the test (intact skin)

Score at time point / Reversibility	Erythema Max. score 4	Oedema Max. score 4
24 h	0.83	0.00
72 h	1	0.83
Average 24h and 72h	0.91	0.41
Reversibility*)	n.	n.
Average time for reversion**	-	-

 *) Reversibility: c. = completely reversible; n.c. = not completely reversible; n. = not reversible

**): correspond to the last day for which skin irritation signs in the last animal were observed

 

Table 7.3.1/2: Irritant/corrosive response data for individual animals at each observation time up to removal of animals from the test (intact skin)

 

Score at time point / Reversibility	Erythema Max. score 4	Oedema Max. score 4
24 h	1 / 0 / 1 / 1 / 1 / 1	0 / 0 / 0 / 0 / 0 / 0
72 h	1 / 0 / 2 / 1 / 1 / 1	0 / 0 / 3 / 0 / 1 / 1
Average 24h and 72h	1 / 0 / 1.5 / 1 / 1 / 1	0 / 0 / 1.5 / 0 / 0.5 / 0.5
Reversibility*)	n.	n.
Average time for reversion**	-	-

 *) Reversibility: c. = completely reversible; n.c. = not completely reversible; n. = not reversible

**): correspond to the last day for which skin irritation signs in the last animal were observed

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the experimental conditions of this study, the test item is not classified as irritant according to Regulation (EC) No 1272/2008 (CLP) and to GHS.

Executive summary:

In a dermal irritation study, 0.5 g of undiluted test material was dermally applied on the intact and abraded skin of 6 albino rabbits. Test sites were covered with an occlusive dressing for 24 h. Skin irritation was assessed and scored according to the Draize scale at 24 and 72 h after the removal of the patch.

The test material induced slight to well defined erythema and slight to moderate oedema to the intact skin but the individual average scores (24/72 h) are rather low (1/0/1.5/1/1/1 and 0/0/1.5/0/0.5/0.5, respectively) and far from average scores leading to classification for skin irritation (<2.3). Moreover, average scores in the abraded skin is similar to that for the intact skin, both under occlusive conditions.

Reversibility is not observed at 72 h but the study terminated after 72 h, with no removal of residue (or at least not reported) after the treatment of test item to the skin and thus no observation period after removal of the substance (recovery period). The average scores observed are low and thus a full recovery could be expected after a normal recovery period of 14 day.

Therefore, under the experimental conditions of this study, the test item is not classified according to Regulation (EC) No 1272/2008 (CLP) and to GHS.

This study is considered as acceptable and satisfies the requirement for skin irritation endpoint.