Abstract: A method of improving the quality of ethylene glycols, particularly monoethylene glycol which is derived from ethylene oxide produced by the direct oxidation of ethylene with air or oxygen is described. The novel method involves the removal of certain impurities from the ethylene oxide producing reaction system prior to the final processing of the ethylene oxide produced to glycol products. In a particular embodiment contaminating impurities are removed from a purge stream taken from the ethylene oxide reaction system and which is utilized in the ethylene glycols reaction system. Removal of the impurities by the preferred method of carbon adsorption produces in the ethylene glycols reaction system, glycols which have improved ultraviolet light transmittance. In particular, monoethylene glycol having an ultraviolet light transmittance rendering it suitable for use in fiber making processes is produced.