3-Methyl-cyclohexanecarboxylic acid methyl ester

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

4 April - 29 July 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study in accordance with recognised test method

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Reference

Name:

Unnamed

Type:

Constituent

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan UK Ltd
- Age at study initiation: 10-12 weeks
- Weight at study initiation: 17.8-22.2 g
- Housing: individually in polycarbonate cages with woodflake bedding
- Diet (e.g. ad libitum): standard rodent diet (Rat and Mouse No. 1 Maintenance Diet)
- Water (e.g. ad libitum): potable water taken from the public supply was freely available via polycarbonate bottles fitted with sipper tubes
- Acclimation period: 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23°C
- Humidity (%): 40-70%
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): artificial lighting was controlled to give a cycle of 12 hours continuous light and 12 hours continuous dark per 24 hours


IN-LIFE DATES: From: 29 April 2008 To: 27 May2008

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

10, 25, 50% w/v

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: the maximum practical concentration for pinna dosing was 50 % v/v in acetone olive oil. Based on this information the following concentration was selected for the preliminary investigation: 50% v/v

- Irritation: no signs of irritation were seen over the dosed area during the study.
- Lymph node proliferation response: not specified


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: animals assigned without conscious bias
- Criteria used to consider a positive response: test/control ratio of three or greater



TREATMENT PREPARATION AND ADMINISTRATION:
Groups of four mice were treated at one of three concentrations of the test substance. The mice were treated by daily application of 25 µl of the appropriate concentration of the test substance to the dorsal surface of each ear for three consecutive days (Days 1-3). The test substance was applied to the dorsal surface of each ear using an automatic micropipette. The test substance was spread over the entire dorsal surface of the ear using the tip of the pipette.

In the main phase of the study, five days following the first topical application of test substance (Day 6) all mice were injected via the tail vein with 250 µl of phosphate buffered saline containing 3H-methyl Thymidine (3HTdR: 80 µCi/ml) giving a nominal 20 µCi to each mouse. The injection into the tail vein was carried out using a plastic syringe and needle after the mouse had been heated in a warming chamber.

Positive control substance(s):

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

Statistics:

Not applicable

Results and discussion

Positive control results:

Refer to attached background material

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: The test substance is regarded as a sensitizer if at least one concentration of the test substance results in a three-fold greater increase in 3HTdR incorporation compared to control values.

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: See remarks on results for DPM table.

Any other information on results incl. tables

Group	Concentration % v/v	dpm	Number of lymph nodes per group	dpm/node	Test/control ratio†	Result + = positive - = negative
2	AOO	4954.30	8.0	619.29	n/a	n/a
3	10	2705.80	8.0	338.23	0.5	-
4	25	4670.30	8.0	583.79	0.9	-
5	50	7403.70	8.0	925.46	1.5	-
†              Test/control of 3 or greater indicates a positive result n/a          Not applicable dpm        Disintegrations per minute (less background count of 106.20 dpm) AOO       Acetone:olive oil (4:1 v/v) (vehicle control)

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

M3MC-Carboxylate is not regarded as a potential skin sensitizer.

Executive summary:

M3MC-Carboxylate is not regarded as a potential skin sensitizer.