1-Ethoxy-2,3-difluoro-4-(trans-4-pentylcyclohexyl)-benzene

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

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

Adequacy of study:

key study

Study period:

May 03 - Jul 24, 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: For this endpoint information from a structural similar compound is available. This study for this similar compound was performed according to GLP and the methods applied are fully compliant with OECD TG 429.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

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:

174350-05-1

Cas Number:

174350-05-1

IUPAC Name:

174350-05-1

Test material form:

other: solid

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: 7 - 8 weeks - Weight at study initiation: 18,5 +/- 1,0- Housing: single- Diet (e.g. ad libitum): ad libitum - Water (e.g. ad libitum): ad libitum - Acclimation period: 7 daysENVIRONMENTAL CONDITIONS- Temperature (°C): 22 + 3°C- Humidity (%): 30-88%- Photoperiod (hrs dark / hrs light): 12/12IN-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 signs of irritation: 2.5, 5, 10 and 25 % (v/v)main test: 5, 10 and 25 % (v/v)

No. of animals per dose:

pre test: 2main test: 5 (f) per group (3 test groups, 1 control group) total 20 (f)

Details on study design:

RANGE FINDING TESTS:- Compound solubility: solubility in vehicle was demonstrated- Irritation: pre test performed- Lymph node proliferation response: no dataMAIN STUDYANIMAL ASSIGNMENT AND TREATMENT- Name of test method: OECD TG 429- Criteria used to consider a positive response: 3-fold greater response at one concentration in SI than control animals TREATMENT PREPARATION AND ADMINISTRATION:a) Topical application of 25 µL test item preparation (test group) or vehicle (control group)b) five days after topical application: iv application of 3H-methyl thymidin c) prior each treatment (a and b) ear thickness measurementd) five hours after treatment (b) necropsy and analysis of the 3H thymidin incorporation in draining lymph nodese) method: pooled per animal

Positive control substance(s):

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

Statistics:

Dunnets Test

Results and discussion

Positive control results:

Conc. SI5%: 2.4310% 4.0725% 4.88

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: Control: Hexylcinnamaldehyde2.5%: 2.435%: 4.0710% 4.88

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: DPM S.I.Control: 508.3 15%: : 930.0 1.8310%: 858.1 1.6925% 530.0 1.04

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

From the data it can be concluded that the test item is not a skin sensitiser under the conditions of this assay.

Executive summary:

Study Design

In the study the test item was dissolved in acetone:olive oil (4+1) was assessed for its possible contact allergenic potential.
For this purpose a local lymph node assay was performed using test item concentrations of 5, 10, and 25%. The GLP study was performed according to OECD TG 429.

Results

The animals did not show any clinical signs during the course of the study and no cases of mortality were observed.
A relevant increase in ear thickness gain could not be observed after treatment with the test item.
In this study Stimulation Indices (S.I.) of 1.83, 1.69, and 1.04 were determined with the test item at concentrations of 5, 10, and 25% in acetone:olive oil (4+1), respectively. Since the S.I. was not increased above 3 at any test group.

Conclusion

From the data it can be concluded that the test item is not a skin sensitiser under the conditions of this assay.