Menthone is a naturally occurring organic compound. It is found in oils of peppermint, Japanese mint, pennyroyal, Micromeria abyssinica benth, geranium and other oils. It is widely used as fragrances and flavors in the cosmetic, perfume, drug, and food industries. Menthone is a naturally occurring pesticide. Menthone and isomenthone were mild skin irritants and of low acute dermal toxicity in rabbits. Neither showed any sensitizing potential in volunteer studies with dilute solutions. In rats, menthone demonstrated a moderate to low acute oral toxicity. On repeated oral administration, menthone produced increases in liver, kidney and spleen weights of rats. Mutagenic activity was reported for menthone in the bacterium Salmonella typhimurium (Ames test) and in fruitflies.