Reaction mass of 3-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde and 4-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 3-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde and 4-(4-hydroxy-4-methylpentyl)cyclohex-3-enecarbaldehyde

EC Number:

915-617-9

Molecular formula:

C13H22O2

IUPAC Name:

Reaction mass of 3-(4-hydroxy-4-methylpentyl)cyclohex-3-ene-1-carbaldehyde and 4-(4-hydroxy-4-methylpentyl)cyclohex-3-enecarbaldehyde

Test material form:

liquid

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Remarks:

CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Netherlands
- Age at study initiation: 7 - 12 weeks
- Weight at study initiation: 13.6 - 21.8 g
- Housing: in groups of 4 in Makrolon type-3 cages with standard softwood bedding
- Diet: pelleted standard Kliba 3433 mouse maintenance diet, ad libitum
- Water: community tap water from Itingen, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30 - 70
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

1, 2.5, 5, 10 and 25 %

No. of animals per dose:

4 females

Details on study design:

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: a test item was regarded as a sensitiser if the following criteria were fulfilled:
a) exposure to at least one concentration of the test item resulted in an incorporation of 3-H-methl thymidine at least 3-fold or greater than recorded in control mice, as indicated by the stimulation index;
b) the data are comparable with a conventional dose response, although allowance must be made (especially at high topical concentrations) for either local toxicity or immunological suppression.

TREATMENT PREPARATION AND ADMINISTRATION:
Each group of mice was treated by epidermal topical application to the dorsal surface of each ear lobe (left and right) with different test item concentrations. The mice of the positive control group (alpha-hexylcinnamaldehyde) were treated in the same way at a concentration of 25 %. The application volume of 25 μL was spread over the entire dorsal surface of each ear lobe once daily for three consecutive days. A further group of mice was treated with an equivalent volume of the relevant vehicle alone. A hair dryer was used to dry the ear's surface as quickly as possible to avoid loss of test item applied.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

Mean values and standard deviations were calculated.

Results and discussion

Positive control results:

Stimulation index of 7.2 for 25 % solution

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

EC3

Value:

0.171

Results 2

Parameter:

SI

Value:

0.6

Test group / Remarks:

1 % (v/v)

Remarks on result:

other: 1%

Results 3

Parameter:

SI

Value:

0.7

Test group / Remarks:

2.5 % (v/v)

Remarks on result:

other: 2.5%

Results 4

Parameter:

SI

Value:

0.6

Test group / Remarks:

5 % (v/v)

Remarks on result:

other: 5%

Results 5

Parameter:

SI

Value:

1.3

Test group / Remarks:

10 % (v/v)

Remarks on result:

other: 10%

Results 6

Parameter:

SI

Value:

4.9

Test group / Remarks:

25 % (v/v)

Remarks on result:

other: 25%

Results 7

Parameter:

other: disintegrations per minute (DPM)

Value:

3 960

Test group / Remarks:

1 % (v/v)

Remarks on result:

other: 1%

Results 8

Parameter:

other: disintegrations per minute (DPM)

Value:

4 687

Test group / Remarks:

2.5 % (v/v)

Remarks on result:

other: 2.5%

Results 9

Parameter:

other: disintegrations per minute (DPM)

Value:

4 063

Test group / Remarks:

5 % (v/v)

Remarks on result:

other: 5%

Results 10

Parameter:

other: disintegrations per minute (DPM)

Value:

8 100

Test group / Remarks:

10 % (v/v)

Remarks on result:

other: 10%

Results 11

Parameter:

other: disintegrations per minute (DPM)

Value:

31 487

Test group / Remarks:

25 % (v/v)

Remarks on result:

other: 25%

Any other information on results incl. tables

No test substance-related clinical signs were observed in any group. The body weight of the animals, recorded at the start of acclimatisation period and prior to necropsy, was within the range commonly recorded for animals of this strain and age.

Applicant's summary and conclusion

Interpretation of results:

other: Skin sensitiser (1A)

Remarks:

in accordance with EU CLP (EC no 1272/2008 and its amendments)

Conclusions:

The test substance is sensitising to skin. The substance is a skin sensitizer (1A) in the Local Lymph Node Assay in mice (OECD TG 429),

Executive summary:

In study, performed according to OECD TG 429 (Local Lymph Node Assay in mice), in compliance with GLP, five groups of 4 female mice were treated by topical application to the dorsal surface of each ear lobe with 1, 2.5, 5, 10 and 25 % solution of test substance in acetone/olive oil (4:1 v/v) for three consecutive days. A positive control group of four mice was treated with alpha-hexylcinnamaldehyde (25 %) and a vehicle control group was treated with the vehicle alone. Five days after the first topical application the mice were injected intravenously into a tail vein with 3H-thymidine, the draining auricular lymph nodes excised, pooled per group and their proliferative capacity measured by the incorporation of 3H-thymidine in a β-scintillation counter. The stimulation indices were 0.6, 0.7, 0.6, 1.3, and 4.9 for 1, 2.5, 5, 10 and 25 % solution of test substance, respectively. For the positive control a stimulation index of 7.2 was obtained. Based on the results of the study, the test substance is considered to give a positive result in the LLNA test.