Methyl iodid is a halogenated hydrocarbon with the molecular formula CH3I and MeI, which is a monoiodine substitution of methan. It has a boiling point of 42.4°C, a relative density of 2.279 (20/4°C), a dense volatile liquid at room temperature, a dipole moment of 1.59D, and a refractive index of 1.5304 (20°C, D), 1.5293 (21°C, D). Methyl iodid is miscible with common organic solvents, slightly soluble in water, soluble in ethanol and ether. The pure product is colorless and has a special smell. It will decompose I2 and become purple when exposed to sunlight. It can be removed by adding metallic copper. A small amount of methyl iodid exists in rice fields.