AbstractAlternative methods for the extraction of unchanged carbon tetrachloride residues from fumigated whole and ground wheat and maize were examined and compared. Amounts of carbon tetrachloride extracted were determined by gas‐liquid chromatography using two separate columns and an electron‐capture detector. A portion of any carbon tetrachloride residue was found to be converted to chloroform by a steam distillation extraction method but not when a cold solvent extraction process was used. In addition, the effectiveness of removal of carbon tetrachloride from wheat and maize during a 3.5 h steam distillation was progressively lessened, in comparison with the cold extraction process, as the length of time that residual fumigant had been associated with the grain increased.The rate of elimination of carbon tetrachloride from wheat and maize during airing at two temperatures was determined and though partially dependent on the temperature of fumigation, airing was consistently more rapid at 25° than at 10°C. Initial residues of 200 to 400 parts/million in whole grains fell to 1 to 10 parts/million when aired for six months in thin layers at 25°C and to 5 to 50 parts/million at WC. Residues in wheat disappeared more rapidly than those in maize. Grinding initially caused a sharp reduction in carbon tetrachloride content but subsequent airing rates were little faster than those of the whole grains.It is concluded that complete elimination of trace amounts of carbon tetrachloride from products of treated grain is unlikely even after milling but the toxicological significance of such residues is unc