Five previously reported measurements of the gas-phase absorption cross section for in the ultraviolet region are reviewed in the light of recent improvements in the determination of vapour pressure. An improved gas-phase absorption cross section at is presented and compared with a cross section derived from absorbance measurements in hexane solution by applying the (refractive index-dependent) Chako correction. The agreement between the measured gas-phase absorption cross section and that derived from the solution phase absorbences is very good. The highest energy absorption band (band G, 209 nm) is suppressed in intensity and shifted lower in energy more than the other two bands, E (254 nm) and G (326 nm).