Gas chromatography was used to determine the concentrations of acrylonitrile, carbon disulfide, carbon tetrachloride, chloropicrin, ethylene dibromide, ethylene dichloride, hydrocyanic acid, methyl bromide, and of fumigant mixtures (on a volume basis) of acrylonitrile-carbon tetrachloride (25–75), carbon disulfide-carbon tetrachloride (20–80), ethylene dichloridecarbon tetrachloride (75–25), and carbon tetrachloride-ethylene dichloride-ethylene dibromide (60–35-5), under conditions of no load and of a load of corn (whole-kernel grade No. 2 yellow) under recirculation of fumigant. Mortality of adults of Tribolium confusum Duv. and Sitopkilus oryza (L.) are included.