Method, composition and system for generating chlorine dioxide gas in a
controlled release manner by combining at least one metal chlorite and a
dry solid hydrophilic material that reacts with the metal chlorite in the
presence of water vapor, but does not react with the metal chlorite in
the substantial absence of liquid water or water vapor to produce
chlorine dioxide gas in a sustained amount of from about 0.001 to 1,000
ppm.