(E)-3-methyl-4-(2,6,6-trimethylcyclohex-2-en-1-yl)but-3-en-2-one

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:

other: Acceptable, well documented publication/ study report which meets basic scientific principles

Remarks:

The detailed protocole description for the Open Application Test was inserted into the study report by mistake. The correct protocole, based on a concurrent study report, is attachede to this endpoint study record for information.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Covered patch test in Rabbit (see attached protocole)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Ionone, methyl-

EC Number:

215-635-0

EC Name:

Ionone, methyl-

Cas Number:

1335-46-2

Molecular formula:

C14H22O

IUPAC Name:

Ionone, methyl

Details on test material:

- Sample No.: 11.549T1/1B

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9 - 12 weeks
- Housing:individually

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

0.5 ml of neat substance

Duration of treatment / exposure:

4 hours

Observation period:

4, 24, 48, and 72 hours
(grading for erythema, edema, cracking and scaling)

Number of animals:

8

Details on study design:

- standard controls: geraniol, cyclamen aldehyde, and diethyl phthalate
- statistics: Wilcoxon Matched-Pairs Signed Rank Test

Results and discussion

In vivo

Results

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

177

Reversibility:

not fully reversible within: 72 h

Any other information on results incl. tables

Under the conditions of this study, the test substance caused moderate irritation to rabbit skin.

At 4 hours, produced marginal to distinct erythema and edema in most rabbits;

at 24 hours, the intensity of erythema and edema increased with 5/8 animals also showing marginal cracking;

at 48 hours, the intensity of erythema and edema stabilized and 6/8 animals had marginal to slight cracking with 1/8 animals having marginal scaling and

at 72 hours, 1/8 rabbits showed no erythema or edema; 7/8 had marginal to distinct erythema and edema; 7/8 had marginal to slight cracking and 5/8 had marginal scaling.

The overall irritation score was 177, mean score per site was 22.13, and mean score per site per day was 5.53.

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Under the conditions of this study, the test substance caused only moderate irritation to rabbit skin.
However, due to the described irritation effects and choosing a conservative approach, methylionone is regarded as irritant to rabbit skin.