25% active silver-based anti-microbial masterbatch formulated specifically for use into acrylic (PMMA) compounds. It achieves high performance at relatively low concentrations with minimal effect on physical properties and is light resistant as well as stable with little or no discoloration with age. It protects parts against staining, odors, and degradation due to fungi, mold, yeasts, mildew, algae and other microbes. It is applicable in injection molding, extrusion, film and is not used against food-borne or disease causing bacteria.