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Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

The skin sensitising potential of Y-15866 was investigated in a Local Lymph Node Assay (LLNA) in mice according to OECD guideline 429 and in compliance with GLP (Vogel, 2010). Based on a preliminary test in two female CBA/CaOlaHsd mice, the undiluted test substance (100%) and dilutions of 25 and 50% (w/v) of the test substance in dimethylformamide (DMF) were selected as treatment concentrations for the main study. In this experiment, 5 female CBA/CaOlaHsd mice per test group were treated with the undiluted or diluted test substance or vehicle alone, respectively. The test substance formulations or the vehicle were applied on the external surface of each ear (25 µL/ear) for three consecutive days. Five days after the first topical application, the cell proliferation of pooled lymph nodes from individual animals was measured by incorporation of ³H-methyl thymidine and expressed as the amount of radioactive disintegration per minute (DPM). The mean DPM/lymph node for each test group was 520.8, 784.6 and 1450.2 at concentrations of 25, 50 and 100% of the test substance, respectively. Treatment with the undiluted test substance (100% concentration) resulted in a statistically significant increase in DPM/lymph node (1450.2) compared to control values (DPM/node = 305.3) and showed a clear dose-response relationship. Based on these results, stimulation indices of 4.75, 2.57 and 1.71 were calculated for the treatment concentrations of 100%, 50% and 25%, respectively. The estimated concentration for a stimulation index of 3 (EC3) was 59.9%. No local or systemic toxicity and no effects on body weights were observed. The historical positive control hexyl cinnamic aldehyde confirmed the sensitivity and reliability of the experimental technique (SI ≥ 3). Under the above mentioned conditions, the test substance was found to be a sensitiser in the LLNA.

Migrated from Short description of key information:
Skin sensitisation (OECD 429): sensitising

Justification for classification or non-classification

The available data on the skin sensitising potential of Y-15866 meet the criteria for classification as Skin Sens. 1B (H317) according to Regulation (EC) 1272/2008 and as Xi (R43) according to Directive 67/548/EEC.