groundnut plants were treated with hexachlorocyclohexane (hch) or 1-naphthyl-n-methylcarbamate (carbaryl) following agricultural practices and the residues were followed in seed and oil. in the oil extracted from kernels of hch treated plants, beta -isomer of hch was present in greater amounts than other isomers. commercial procedures like alkali refining and bleaching did not remove exp 14 c radioactivity from exp 14 c alpha - or beta - or gamma -hch fortified groundnut oil. deodorisation procedure had removed 86 and 94 of alpha - and gamma -hch radioactivity. however with beta -isomer only 56 exp 14 c radioactivity was removed. experiments with unlabelled and labelled carbaryl showed that in oil extracted from kernels of carbaryl treated plants, residues as carbaryl were not present alkali refining and bleaching had together removed 76 of total exp 14 c radioactivity initially added. however, deodorisation procedures could remove only 23 of exp 14 c radioactivity. the significance of the above results is discussed. (atomindex citation 09:404797)