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

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

The test material is not the full substance (methyl ionone) but the pure main constituent (alpha-isomethyl ionone) from which a read-across is possible. The test material was tested only at 12.5%. Nevertheless, as the substance is classified as eye irritant based on this data, these restrictions are considered acceptable.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1963

Report date:

1963

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Principles of method if other than guideline:

Test material (0.1 ml) was instilled into the right eye of 3 albino rabbits with no further treatment. The untreated left eye served as a control. Both eyes were examined every 24 hours for 4 days and on day 7. Scoring was according to the Draize scale for ocular lesions.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one

EC Number:

204-846-3

EC Name:

3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one

Cas Number:

127-51-5

Molecular formula:

C14H22O

IUPAC Name:

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

Constituent 2

Reference substance name:

Reference substance 001

Cas Number:

127-51-5

Test animals / tissue source

Species:

rabbit

Strain:

other: stated as "albino"

Test system

Vehicle:

not specified

Controls:

other: left eye

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml
- Concentration (if solution): 12.5 %

Duration of treatment / exposure:

single application, substance remains in eye

Observation period (in vivo):

Both eyes were examined every 24 hours for 4 days and on day 7.

Number of animals or in vitro replicates:

3

Details on study design:

SCORING SYSTEM: acc. Draize scale for ocular lesions

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

>= 2

Max. score:

3

Reversibility:

fully reversible within: 7 d

Results 2

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Results 3

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

0

Max. score:

2

Reversibility:

other: not applicable

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

> 1

Max. score:

4

Reversibility:

fully reversible within: 7 d

Any other information on results incl. tables

12.5 %: irritant effects

- intense conjunctival irritation from days 1 to 4 involving chemosis and discharge that cleared by day 7

- no corneal opacity or iris congestion

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

In this eye irritation study, fully reversible irritant effects were observed when a 12.5% solution of alpha-isomethyl ionone (the pure main constituent and structural analogue of methyl ionone) was used.
Due to the clearly described irritation effects, the analogue alpha-isomethyl ionone is regarded as an eye irritant. Choosing a conservative approach, an eye irritating potential is also assumed for the target substance methylionone.