摘要 |
The invention serves to prevent or delay the formation of undesired phosphine levels in packages in which phosphine releasing compositions (in particular hydrolysable metal phosphides) are packaged and stored and in environments to be fumigated during the period of introduction of phosphine-releasing compositions. This is brought about by maintaining in the immediate vicinity of the composition a zeolite having a pore width from 0.3 nm upwards, preferably 0.4 to 1.5 nm and an adsorbtive affinity for moisture or phosphine or preferably both. The zeolite is employed either as a separate item in the package or as part of the composition, admixed or as a coating. In a mass ratio of metal phosphide to zeolite are from 1:0.05 to 1:2. The adsorption of phosphine to the zeolite is reversible and on exposure to an environment to be subjected to pest control, the zeolite will release the adsorbed phosphine by replacement by atmospheric humidity. The zeolite loaded with phosphine is itself useful as a pest control agent. |