Truck-ship containers in three sizes (20, 35, and 40 ft) were fumigated loaded or empty, stationary or in transit. The three hydrogen phosphide sources used extensively in the studies controlled test insects effectively and left residues that were generally below tolerance levels set by the US Environmental Protection Agency. Besides bioassays and residue analyses, studies were done on container sealing, aeration, and simulated accidents. The resulting data show that, under the conditions prevalent during the tests, in-transit fumigation of these containers can be done safely and effectively.