Registration Dossier

Administrative data

Description of key information

Oral (OECD 423), rat (f): LD50 > 5000 mg/kg bw (limit test)
Dermal (OECD 402), rat (m/f): LD50 > 2000 mg/kg bw (limit test)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
5 000 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
2 000 mg/kg bw

Additional information


The acute oral toxicity of Y-15866 was investigated in a GLP-conform study according to the acute toxic class method (OECD guideline 423). Two groups, each consisting of 3 female RccHan:WIST rats, were treated with Y-15866 diluted in PEG 300 as vehicle by single oral gavage administration at a limit dose of 2000 mg/kg bw (Arcelin, 2010). No mortality occurred during the study period. Slightly ruffled fur was observed in all 6 animals 2 h after test substance administration. The ruffled fur persisted with the same severity in 2 animals at the 3 h reading. All 6 animals were free of clinical signs from the 5 h reading to the end of the study (on Day 15). No effects on body weights were observed and necropsy revealed no substance-related findings. Based on these experimental results, the LD50 of Y-15866 was greater than 2000 mg/kg bw. According to the criteria of OECD guideline 423, the LD50 cut-off of Y-15866 may be considered to be greater than 5000 mg/kg bw.


The acute dermal toxicity of Y-15866 was tested in accordance with OECD guideline 402 and in compliance with GLP (Arcelin, 2011). The study was performed as a limit test in RccHan: WIST rats (5 males and 5 females) at a dose of 2000 mg/kg bw. The test substance was applied at a concentration of 50% (w/w) in polyethylene glycol 300 (PEG 300) onto the clipped skin of the test animals for 24 h under semiocclusive conditions. After removal of the test substance, animals were observed for a period of 14 days. No local dermal signs were noted during the course of the study with the exception of one male, which showed very slight erythema at the application site on Day 2 after treatment. No mortalities and no signs of systemic toxicity were observed. The body weight evolution in all animals was not affected by treatment. No macroscopic findings were recorded at necropsy. Based on these results, the dermal LD50 value for male and female rats was greater than 2000 mg/kg bw.

Justification for classification or non-classification

The available data on the acute toxicity of Y-15866 do not meet the criteria for classification according to Regulation (EC) 1272/2008 (CLP) or Directive 67/548/EEC (DSD), and are therefore conclusive but not sufficient for classification.