(E)-1-(2,6,6-trimethyl-1-cyclohexen-1-yl)pent-1-en-3-one

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP study conducted similarly to OECD Guideline No. 404 with deviations: details on test item and age/weight of animals at study initiation not reported. Observation period of 7 days only, with non-reversible effects at the end of the observation period. The supporting substance is considered adequate for read-across purpose as data relates to an isomer of the registered substance (see Iuclid section 13 for additional justification).

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

details of test item and age/weight of animals at study initiation not reported; relative humidity slightly exceeds the range, observation period only up to 7 days (168h)

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

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

Test material form:

not specified

Details on test material:

None

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Housing: Animals were individually housed in anodised aluminium cages with grid floors
- Diet: Commercially available Pelleted rabbit diet (S.Q.C. Standard Rabbit Diet, Special Diet Services Limited, Witham, Essex), ad libitum
- Water: Mains tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18-23 °C
- Humidity: 40-80 %
- Air changes: Animal room was air conditioned
- Photoperiod: 12 h dark / 12 h light

Test system

Type of coverage:

semiocclusive

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): No preparation of the supplied materials was necessary except for materials which were tested as powdered solids, 0.5 g aliquots being moistened with 0.5 ml distilled water

Duration of treatment / exposure:

4 h

Observation period:

1, 24, 48, 72 and 168 h (7days) after removal of patches

Number of animals:

3 females

Details on study design:

TEST SITE: Intact skin
- Type of wrap if used: 0.5 mL of a liquid test material or an aliquot of a paste prepared from a solid material, the aliquot containing 0.5 g of the original material was placed evenly over a 2.5 cm square of surgical lint B.P. The lint square was then placed onto the animal's skin, on the left flank and immediately caudal to the last rib, with the test material in contact with the skin. The lint patches were held in place by encircling the trunk of the animal with a length of 'Elastoplast' elastic adhesive bandage 10 cm wide.

REMOVAL OF TEST SUBSTANCE
- Washing: After a period of four hours the adhesive tapes were removed and the treated sites cleansed by gentle swabbing with cotton wool soaked in warm water. The animals were then returned to their cages.
- Time after start of exposure: 4 h

SCORING SYSTEM: Draize scale, as described in OECD Guideline No. 404

OTHERS:
Animals were examined under a standard light source designed to comply with the requirements of B.S. 950 Part 1 (Artificial Daylight for the Assessment of Colour).

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: mean 24, 48 and 72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 168 h

Results 2

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: mean 24, 48 and 72 h

Score:

1.3

Max. score:

4

Reversibility:

not fully reversible within: 168 h

Results 3

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: mean 24, 48 and 72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 168 h

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: mean 24, 48 and 72 h

Score:

2.7

Max. score:

4

Reversibility:

not fully reversible within: 168 h

Results 5

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

other: mean 24, 48 and 72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 168 h

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: mean 24, 48 and 72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 168 h

Irritant / corrosive response data:

- One hour after dosing, well defined erythema and slight oedema was observed at the treated site of two rabbits and very slight erythema with slight oedema was observed in the remaining rabbit.
- At 24 h observation, well defined erythema and slight oedema was observed in two rabbits and the treated site of the remaining rabbit exhibited well defined erythema and moderate oedema.
- Slight changes in the oedematous response of two rabbits were apparent 48 h after dosing when slight oedema was observed at two sites and the treated site of one animal exhibited very slight reaction.
- Moderate oedema was again observed in one rabbit 72 h after dosing, other irritant reactions remaining unchanged.
- At 168 h observation (7days), one rabbit showed very slight erythema and oedema and one rabbit exhibited well defined erythema and very slight oedema, both animals with desquamation from the surface of the treated skin. The remaining animal of the group exhibited well defined erythema, slight oedema and marked desquamation from the skin surface.
- Reversibility was not observed in any of the treated rabbits.

Other effects:

None

Any other information on results incl. tables

Table 7.3.1/1: Mean irritant/corrosive response data for each animal at each observation time

Score at time point	Erythema (Animal no 1 / 2 / 3) Max. score 4	Oedema (Animal no 1 / 2 / 3) Max. score 4
1 h	1 / 2 / 2	2 / 2 / 2
24 h	2 / 2 / 2	2 / 3 / 2
48 h	2 / 2 / 2	1 / 2 / 2
72 h	2 / 2 / 2	1 / 3 / 2
168 h	1 / 2 / 2	1 / 2 / 1
Average 24, 48 and 72 h	2.0 / 2.0 / 2.0	1.3 / 2.7 / 2.0

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information according to CLP criteria Criteria used for interpretation of results: EU

Conclusions:

Under the test conditions, test material is classified as "Category 2: irritant" according to Regulation (EC) No. 1272/2008 (CLP)

Executive summary:

In a dermal irritation study performed similarly 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 flank area of 3 female New Zealand White rabbits. Test sites were covered with a semi-occlusive dressing for 4 h. Skin irritation was assessed and scored according to the Draize scale at 1, 24, 48, 72 and 168 h after removal of the patches. One hour after dosing, very slight to well defined erythema and slight oedema were observed. At 24 h observation, well defined erythema and slight to moderate oedema were observed. Very slight to slight oedematous response was observed at 48 h after dosing. Moderate oedema was again observed in one rabbit 72 h after dosing, other irritant reactions remaining unchanged. The individual scores for each animal within 3 scoring times (24, 48 and 72 h) were 2.0 / 2.0 / 2.0 for erythema and 1.3 / 2.7 / 2.0 for oedema. At 168 h observation, very slight to well defined erythema and oedema were observed; animals exhibited desquamation from the surface of the treated skin. Reversibility was not observed in any of the treated rabbits.   Under the test conditions, test material is classified as "Category 2: irritant" according to Regulation (EC) No. 1272/2008 (CLP). This study is considered as acceptable and satisfies the requirement for skin irritation endpoint. The supporting substance is considered adequate for read-across purpose as data relates to an isomer of the registered substance (see Iuclid section 13 for additional justification).