Cellulose sponge stays fresh longer. Resists odors, staining and crumbling. Features 3M’s unique anti microbial technology integrated into every fiber. Sponge resists the growth of odorcausing bacteria through hundreds of uses.Scotch-Brite Sponge A21 features 3M's antimicrobial technology that helps it resist the growth of odour-causing bacteria through hundreds of uses.