Colorless transparent liquid. Has a pungent odor. It is gradually oxidized to isobutyric acid in the air. Slightly soluble in water, miscible with ethanol, benzene, chloroform, ether, toluene, acetone and carbon disulfide. The solubility in water at 20°C is 11G/100ml. Relative density (d204) 0.7938. Melting point -65.9 ℃. Boiling point 64 ℃. Refractive index (n20D) 1.373. Flash point -6.7 ℃ (open cup). Flammable. Low toxicity, median lethal dose (rat, oral) 2810mG/kG.