this invention relates to a method of fumigating agricultural products in storage or transportation facilities for controlling pests by means of hydrogen phosphide which is then bound and / or decomposed to a substantial extent ; according to the invention , a fumigating composition releasing hydrogen phosphide is placed in a manner known per se among products stored in conventional storage facilities , whereupon the stored products are covered with a flexible film , foil or sheet to isolate them from the surrounding storage space , and the hydrogen phosphide diffusing from the gas containing space above and among the stored products during or after fumigation is bound by adsorption , physical or chemical absorption and / or decomposed by chemical or physical means . the invention also relates to a specific solid catalyst suitable for the decomposition of hydrogen phosphide .