Cyclohexanone

Endpoint summary

Additional information

In a subchronic drinking water study according to OECD guideline 408 (study duration: 3 months) rats were given 500, 2000 and 7000 ppm (about 40, 143 and 407 mg/kg). The NOAEL was found to be 143 mg/kg. Decreases in water consumption in all three concentrations and decreases in food consumption in the mid and high dose groups. 10% reduction of body weights of the animals treated with the high concentrations. Increases in total cholesterol, total protein, globulins and platelets in the high dose group (BASF, 1994).

In a 2-year drinking water study (Lijinsky and Kovatch, 1986) with rats and mice with doses ranging from 3300 - 25000 ppm the following NOAEL was established: 462 mg/kg for male and female rats (= 3300 ppm). The LOAEL for male and female rats was 910 mg/kg (= 6500 ppm). A NOAEL resp. LOAEL for mice was not identified. Slight liver changes were observed in high dose animals.

Greener et al. (1982) reported an assessment of the toxicity to cyclohexanone administered intravenously to Wistar and Gunn rats. Male animals were given intraveneously doses of 50 or 100 mg/kg over a study period of 28 days. The authors concluded, that the Gunn rat, despite its inability to form glucuronide conjugates of bilirubin, is capable of forming glucuronide conjugates of cyclohexanol after administration of cyclohexanone. With the dose schedule employed in this study, there was neither accumulation nor evidence of potential toxicity in Wistar and Gunn rats when cyclohexanone was administered i.v. for 28 consecutive days. The NOAEL was found to be 100 mg/kg (for both strains).

Justification for classification or non-classification

Since the above described effects were only seen in high-dosed animals, classification is not warranted.