Colorless transparent liquid. There is a smell similar to acetone. volatile. With ethanol, ethyl ether, benzene, chloroform, oil immiscibility. It dissolves in 4 parts of water, but its solubility decreases when the temperature rises. It can form an azeotropic mixture with water (11.3% water content) and azeotropic point of 73.4°C (88.7% butanone). Relative density (d204) 0.805. Freezing point -86°C. The boiling point 79.6 °C. The refractive index (n15D) is 1.3814. Flash point 1.1°C. Low toxicity, median lethal dose (rat, oral) 3300mG/kG. Flammable, vapor can form an explosive mixture with air, explosion limit of 1.81% to 11.5% (volume). High concentrations of vapor have narcotic.