4-Ethyl-2',3'-difluor-4''-propyl-1,1':4',1''-terphenyl

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

April 13 - June 08, 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

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

Test material information

Constituent 1

Reference substance name:

4'-ethyl-2,3-difluoro-4-(4-propylphenyl)-1,1'-biphenyl

EC Number:

605-092-1

Cas Number:

157248-25-4

Molecular formula:

C₂₃H₂₂F₂

IUPAC Name:

4'-ethyl-2,3-difluoro-4-(4-propylphenyl)-1,1'-biphenyl

Test material form:

solid: bulk

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: 20.1 +/- 1.6 g
- Housing: single
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 + 2°C
- Humidity (%): 45-65%
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: day 1 To: day 6

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

10, 25, and 50 % (w/w)

No. of animals per dose:

5

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: 25 and 50 %
- Irritation: No
- Lymph node proliferation response: -

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: OECD 429
- Criteria used to consider a positive response: Stimulation index > 3

TREATMENT PREPARATION AND ADMINISTRATION:

Positive control substance(s):

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

Statistics:

Standard statistical methods have been applied for data processing.

Results and discussion

Positive control results:

Conc. SI
0%: 1.00
5% 1.78
10% 2.54
25% 4.88

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

1.26

Test group / Remarks:

Test Group: 10%

Results 2

Key result

Parameter:

SI

Value:

0.91

Test group / Remarks:

Test Group: 25%

Results 3

Key result

Parameter:

SI

Value:

0.65

Test group / Remarks:

Test Group: 50%

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA
Test item concentration DPM per lymph node
Vehicle 822.9
10% 1034.8
25% 751.3
50% 535.8

EC3 CALCULATION : Could not be calculated, since all S.I.s are below 3.

CLINICAL OBSERVATIONS: No deaths occurred during the study period. No symptoms of local toxicity at the ears of the animals and no systemic findings were observed during the study period.

BODY WEIGHTS: The body weight of the animals, recorded prior to the first application and prior to
treatment with 3HTdR, was within the range commonly recorded for animals of this strain and age.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was not a skin sensitiser under the test conditions of this study.

Executive summary:

Objective

The purpose of this Local Lymph Node assay was to identify the contact allergenic potential of the test material when administered to the dorsum of both ears of mice.

This study should provide a rational basis for risk assessment to the sensitising potential of the test item in man.

Study Design

In order to study a possible allergenic potential of the test material, three groups each of five female mice were treated with different concentrations of the test item by

topical application at the dorsum of each ear (left and right) on three consecutive days. A control group of five mice was treated with the vehicle only. Five days after the first topical

application, the mice were intravenously injected into a tail vein with radio-labelled thymidine (3H-methyl thymidine). Approximately five hours after intravenous injection, the

mice were sacrificed and the draining auricular lymph nodes excised and pooled per animal. Single cell suspensions of lymph node cells were prepared from pooled lymph

nodes, which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation

of 3H-methyl thymidine measured in a beta-scintillation counter.

Results

The animals did not show any signs of local irritation or systemic toxicity during the course of the study and no cases of mortality were observed.

In this study Stimulation Indices (S.I.) of 1.26, 0.91, and 0.65 were determined with the test item at concentrations of 10, 25, and 50% in acetone:olive oil (4+1), respectively.

Conclusion

The test item was not a skin sensitiser under the test conditions of this study.