ABSTRACT
4-Benzylphenol (CAS No. 101-53-1), a structural analog of bisphenol F, has estrogenic activity in vitro and in vivo, as is the case with bisphenol F. 4-Benzylphenol is used in plastics and during organic synthesis. Since its safety is largely unknown, we conducted toxicity tests as part of screening risk assessment in an existing chemical safety survey program. Based on results of the Ames test and the chromosomal aberration test using Chinese hamster lung cells (OECD TG 471 and 473), 4-benzylphenol was determined to be non-genotoxic in vitro. In a 28-day repeated-dose toxicity study, Crl:CD (SD) rats were administrated 4-benzylphenol by gavage at 0, 30, 150, or 750â¯mg/kg/day (OECD TG 407). Consequently, body weight was lower in males at 750â¯mg/kg/day. In the liver, relative organ weights were increased in both sexes at 750â¯mg/kg/day, and centrilobular hepatocellular hypertrophy was observed in males at 150 and 750â¯mg/kg/day. In the forestomach, hyperkeratosis and hyperplasia of squamous cells were observed in males at 150 and 750â¯mg/kg/day, and in females at 750â¯mg/kg/day. Based on these results, we identified the NOAEL for 4-benzylphenol as 30â¯mg/kg/day, with a hazard assessment value (D-value) of 0.05â¯mg/kg/day corresponding to hazard class 3.
Subject(s)
Benzhydryl Compounds/toxicity , Chromosome Aberrations/drug effects , Mutagens/toxicity , Administration, Oral , Animals , Benzhydryl Compounds/administration & dosage , Benzhydryl Compounds/chemistry , CHO Cells , Cricetulus , Dose-Response Relationship, Drug , Female , Male , Molecular Structure , Mutagens/administration & dosage , Mutagens/chemistry , Organ Size/drug effects , Rats , Rats, Sprague-Dawley , Time FactorsABSTRACT
Three female Crl:CD(SD) rats/group were dosed with single wall carbon nanotube (SWCNT) or multi wall carbon nanotube (MWCNT) four times by gavage at a total of 50 mg/kg bw or 200 mg/kg bw (four equally divided doses at one-hour intervals). Acute oral doses of SWCNT and MWCNT caused neither death nor toxicological effects, and thus the oral LD