When a 0.6 g aluminum phosphide pellet was applied to groundnuts in a jute or woven polypropylene sack, of 32-82 kg capacity and lined with polyethylene 63.5-127.5 mu thick, the C x T product for phophine exceeded 50 mg hr/l, and 100 per cent mortality of all stages of Tribolium castaneum (Herbst), Oryzaephilus surinamensis (L) and Sitophilus zeamais Motsch. was recorded, but no residue was found when pellets were enclosed in paper envelopes. Many liners in sacks of groundnuts transported from Zambia to Britain split, but this did not affect the efficiency of the phosphine fumigation or permit reinfestation. When lined sacks of groundnuts were pierced with a sampling probe 72 hr. after treatment, the efficiency of the phosphine fumigation was not affected, and the sacks were not penetrated by insects even after 70 days in a heavily infested store. The fumigation with phosphine, storage, and transportation in polyethylene-lined sacks did not affect the flavour, moisture content, aflatoxin content, or physical condition of groundnuts. All experimental consignments were commercially acceptable for confectionery purposes in Britain.