Cyclohexanone is a colorless oily liquid with an odor resembling acetone and peppermint. Cyclohexanone is occasionally found as a volatile component of human urine. Biological fluids such as blood and urine have been shown to contain a large number of components, some of them volatiles (low boiling point) apparently present in all individuals, while others such are much more variable. In some cases differences up to an order of magnitude are observed. Although some of these changes may have dietary origins, others seem to be characteristic of the individual. Cyclohexanone is obtained through oxidation of cyclohexane or dehydrogenation of phenol. Approx. 95% of its manufacturing is used for the production of nylon. Information on toxicity to human beings is fragmentary. Acute exposure is characterized by irritation of the eyes, nose, and throat. In two persons, drowsiness and renal impairment were found; however, these workers were also exposed to other compounds. Hepatic disorders were found in a group of workers exposed for over five years. In animals, cyclohexanone is characterized by relatively low acute toxicity (DL50 by intragastric administration is approximately 2 g/kg body wt.). Effects on the central nervous system (CNS) were found (narcosis), as well as irritation of the eyes and skin. Following multiple administration, effects were found in the CNS, liver, and kidneys as well as irritation of the conjunctiva. Mutagenic and genotoxic effects were found, but no teratogenic effects were detected; however, there were embryotoxic effects and influence on reproduction Cyclohexanone is well absorbed through the skin, respiratory tract, and alimentary tract. The main metabolic pathway leads to cyclohexanol, which is excreted in urine coupled with glucuronic acid. A high correlation was found between the concentration of cyclohexanone in the working environment and its concentration in urine. Cyclohexanone is formed from the hydrocarbons cyclohexane and 1-, 2-, and 3-hexanol. A patient's case report documents the development of anosmia (an olfactory disorder) and rhinitis caused by occupational exposure to organic solvents, including cyclohexanone (PMID:10476412, 16925936, 16477465).