The present invention relates to a package that includes an enclosure having a first substance and a second substance within the enclosure. The package further includes a plastic zipper which segregates the first substance from the second substance within the enclosure such that opening the plastic zipper allows the first substance and the second substance to be mixed together inside the enclosure. In another aspect, the package includes a gas-permeable enclosure and first and second solid substances stored within the enclosure. A mechanism, such as a plastic zipper, segregates the first and second solid substances. Opening the mechanism allows a user to mix the first and second solid substances inside the enclosure to produce a gas. The package permits the gas that is produced to permeate through the gas-permeable enclosure for distribution throughout an area.