A gas chromatographic procedure is described for the quantitative determinations of ethylene chlorohydrin and ethylene glycol in disposable medical-grade plastics. Both components are isolated by solvent extraction. The lower limit of detection is 1 p.p.m. of ethylene chlorohydrin and 2 p.p.m. of ethylene glycol. Propylene glycol is used as an internal standard. Ethylene oxide residues have to be removed prior to the assay.