Abstract: The invention provides a preservative gas generating device which has a carrier sheet (6); a layer of a matrix forming material having a preservative gas generating compound dispersed therein (8), the layer of matrix forming material being adapted to permit the generation of a preservative gas by the preservative gas generating compound and to permit the gas to permeate out of the matrix formed by the material, the matrix forming material being adhered to the carrier sheet (6) in the form of a layer covering an area of the carrier sheet so as to form at least one discrete zone (8) with a peripheral area of the carrier sheet surrounding the discrete zone(s) being substantially free of the matrix forming material; and a cover sheet (10) secured to said peripheral area to enclose the layer of matrix forming material between the carrier sheet and the cover sheet; and wherein at least one of the carrier sheet and the cover sheet are permeable to said preservative gas.