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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2003-07-11 to 2003-10-13
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report date:
2003

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Version / remarks:
adopted 24 April 2002
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Chemical structure
Reference substance name:
1-[4-(trans-4-ethylcyclohexyl)-1-cyclohexen-1-yl]-3,5-difluorobenzene
EC Number:
612-166-7
Cas Number:
615257-52-8
Molecular formula:
C20H26F2
IUPAC Name:
1-[4-(trans-4-ethylcyclohexyl)-1-cyclohexen-1-yl]-3,5-difluorobenzene

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Netherlands, B.V. Postbus 6174, NL - 5960 AD Horst
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 17.6 - 25.0 g
- Housing: groups of 4
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30 - 70%
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: day 1 To: day 5

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
pre-test for irritation: 1, 2.5, 5 and 10 % (w/v)
main test: 2.5, 5 and 10 % (w/v)
No. of animals per dose:
pre test: 2
main test: 4 (f) per group (3 test groups, 1 control group) total 16 (f)
Details on study design:
RANGE FINDING TESTS:
In a non-GLP conform pre-test in two mice, test item concentrations of 1 %, 2.5 %, 5 % and 10 % (w/v) were tested on one ear each. No irritation effects were observed at these concentrations after a single application. 10 % (w/v) was the highest technically achievable concentration in the chosen vehicle.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: OECD TG 429
- Criteria used to consider a positive response: A test item is regarded as a sensitizer in the LLNA if the following criteria are fulfilled:
- First, that exposure to at least one concentration of the test item resulted in an incorporation of 3HTdR at least 3-fold or greater than that recorded in control mice, as indicated by the stimulation index.
- Second, that the data are compatible 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:
- Topical application of 25 µL test item preparation (test group) or vehicle (control group)
- five days after topical application: iv application of 3H-methyl thymidine
- five hours after treatment with 3H-methyl thymidine, necropsy and analysis of the 3H thymidine incorporation in draining lymph nodes
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
Dunnets Test

Results and discussion

Positive control results:
alpha-hexylcinnamaldehyde:
5% : S.I=1.5
10%: S.I.=3.2
25%: S.I.=6.9

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
SI
Value:
2
Test group / Remarks:
Test Group 2.5 %
Key result
Parameter:
SI
Value:
2.3
Test group / Remarks:
Test Group: 5 %
Key result
Parameter:
SI
Value:
2
Test group / Remarks:
Test Group: 10 %

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test item was found to be not a skin sensitiser under the described conditions in this assay.
Executive summary:

A LLNA study according to OECD 429 was performed in order to study a possible contact allergenic potential of the test material, three groups each of four female mice were treated daily with the test item at concentrations of 2.5, 5 and 10 % (w/v) in acetone:olive oil, 4:1 (v/v) by topical application to the dorsum of each ear lobe (left and right) for three consecutive days. 10 % was the highest technically achievable concentration in the vehicle.

The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. In this study Stimulation Indices (S.I.) of 2., 2.3 and 2.0 were determined with the test item at concentrations of 2.5, 5, and 10 % in acetone:olive oil, 4:1 (v/v), respectively.

The test material was found to be not a skin sensitiser up to the highest technically achievable concentration of 10 % in the selected vehicle.