4-Butyl-4''-ethyl-2',3'-difluor-1,1':4',1''-terphenyl

Endpoint summary

Description of key information

Skin irritation: No skin irritating potential could be detected for the read-across source substance.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation, other

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

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. See chapter 13 report for a more detailed justification.

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

SI

Value:

1.26

Test group / Remarks:

Test Group 10 %

Key result

Parameter:

SI

Value:

1.26

Test group / Remarks:

Test Group 25 %

Key result

Parameter:

SI

Value:

1.26

Test group / Remarks:

Test Group 50 %

Respiratory sensitisation

Endpoint conclusion

Additional information:

No study data with the test item is available for this endpoint. Therefore, a read-across to the read-across source substance with a very similar chemical structure and comparable physico-chemical parameters is used to evaluate the endpoint for the test item.

 

Skin sensitisaton

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.

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.

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.

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

 

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on available data on skin sensitisation the test item is not considered to be classified according Regulation (EC) No 1272/2008.