Plastics and coatings are provided outstanding antimicrobial activity by incorporation therein of elemental silver and silver supported on a zeolite or on a glass. The compositions are suitable for medical use, for example for tubes, catheters, textiles and the like. The plastic textiles are woven or nonwoven. The plastics are for example polyurethane, polycarbonate, liquid silicone rubber, polypropylene or polyethylene or polymer composites.