Registration Dossier

Administrative data

Description of key information

An OECD combined repeat dose and reproduction toxicity screening test (OECD TG 422) was performed for 6-tert-butyl-m-cresol. SD (Crj:CD) rats received gavage doses of 0 (vehicle, corn oil), 2.5, 12.5 and 60 mg/kg/day. Males were dosed for 42 days and females were dosed from 14 days before maiting, throughout pregnancy until day 3 of lactation. No animal died in any group. No significant clinical sign was observed in any group.  Suppression of body weight gain and decrease in food consumption were observed in females of the 60 mg/kg group, along with liver weight increase.. Histopathological examination revealed hypertrophy of centrilobular hepatocytes in males and females of the 60 mg/kg group. Whereas increase in the kidney weight was found in both sexes given 60 mg/kg, there were no adverse effects by histopathological examination. No significant effect was observed in hematology, urinalysis and blood biochemical parameters for males (these endpoints were not tested in females).  The NOAEL for repeated dose toxicity is considered to be 12.5 mg/kg/day for both sexes

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
12.5 mg/kg bw/day

Additional information

6-tert-butyl-m-cresol shall be registrated according REACH Article 18 (transported isolated intermediate) an no studies for repeated dose are required according REACH Annex VII. Further testing is not justified on scientific and animal welfare grounds.

However a combined repeated dose toxicity study with the reproduction/developmental toxicity screening test according OECD TG was performed. According this study the NOAEL = 12.5 mg/kg/day.

Repeated dose toxicity: via oral route - systemic effects (target organ) digestive: liver

Justification for classification or non-classification

findings are not severe enough for a classification of 6 -tert-butyl-m-cresol