Since W.W.II, Silica Gel has been the desiccant of choice by government and industry for use within enclosed storage areas. Requiring no electricity, Silica Gel is in the form of chemically inert granules which are nontoxic and safe to use with sensitive material ... even food and medicines. These man made granules contain thousands of tiny crevices which literally "drink up" moisture from the air by surface adsorption to create a protective shield of dry air within any enclosed area.