The growing resistance in Australia of stored grain insects to contact insecticides has led to increased interest in the development of physical methods of insect control. At the same time the industry is placing more reliance upon rapid disinfestation using fumigants such as methyl bromide to guarantee insect-free exports. If a physical process could be developed to rapidly disinfest large quantities of grain with no adverse side-effects and at an acceptable cost, it could find widespread application - particularly at export terminals.