The diminishing availability of fumigant compounds makes it essential to improve fumigation techniques if adequate pest control is to be maintained. Three approaches developed by DEGESCH are discussed. Phosphine fumigation is now possible in cold weather if magnesium phosphide rather than aluminium phosphide is used as the source. Gas recirculation (the J‐system) provides for much more rapid fumigation in large grain silos. Finally, techniques are being developed to allow material to be added to, or removed from, a store during fumigation without hazard to the applicato