3-Pyridinecarbonitrile, 4-methyl-2,6-bis[(4-methylphenyl)amino]-5-[2-[2-(trifluoromethyl)phenyl]diazenyl]-

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In order to study a possible allergenic potential of test item, three groups each of four female mice were treated daily with the test item at concentrations of 1 %, 2.5 % and 5 % (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. A control group of four mice was treated with the vehicle (acetone:olive oil, 4:1 (v/v)) only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (H-methyl thymidine). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes excised and pooled per group. 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 activity of pooled lymph node cells was determined by the incorporation of 3H-methyl thymidine measured in a p-scintillation counter. No test item-related clinical signs were observed. All treated animals survived the scheduled study period.

In this study Stimulation indices (S.I.) of 1.3, 0.8 and 1.0 were determined with the test item at concentrations of 1 %, 2.5 % and 5 % (w/v) in acetone:olive oil, 4:1 (v/v). A test item is regarded as a sensitizer in the LLNA if the exposure to one or more test concentrations resulted in 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation indidex. The test item was found to be a non-sensitizer when tested at concentrations of up to 5 % (w/v).

Migrated from Short description of key information:
A possible contact allergenic potential of the test item as described in section 1.2 was determined in a GLP-compliant local lymph node assay (OECD 429) in mice. The test item was found to be a non-sensitizer when tested at concentrations of up to 5 % (w/v) which was the higest applicable dose (RCC 2003).

Justification for classification or non-classification

Based on the available data, the test item does not need to be classified or labelled for skin sensitization according to Directive 67/548/EEC (DSD) and Regulation 1272/2008 EC (CLP).