Chlorine dioxide gas releasing package label insert for enhancing microbial safety of food

A method of killing microorganisms on an item, said method comprising (i) placing said item in a package with a chlorine dioxide releasing package label/insert or (ii) placing a chlorine dioxide releasing package label/insert in an outer plastic bag containing several individual packages containing said item, wherein said chlorine dioxide releasing package label/insert comprises (a) at least one solid layer of pectin and citric acid, (b) at least one solid layer of gelatin and sodium chlorite, (c) optionally at least one solid barrier layer (for controlling the release of gaseous chlorine) comprising gelatin between said at least one layer of pectin and citric acid and said at least one layer of gelatin and sodium chlorite, and (d) an adhesive joining said layers, wherein said package label/insert has alternating layers of said at least one layer of pectin and citric acid and said at least one layer of gelatin and sodium chlorite, and (iii) applying pressure with or without heat to said package label/insert to cause said citric acid to come into contact with said sodium chlorite to produce ClO2, wherein said package label releases ClO2 at concentrations of about 0.5 to about 20 mg/L air.