A silicone rubber exhibiting antimicrobial efficacy contains: a) at least one silicone rubber derived from a curable silicone rubber-forming composition b) at least one silver-containing antimicrobial agent incorporated in silicone rubber (a) in X weight percent amount and, c) at least one carboxylic acid incorporated in silicone rubber (a) in Y weight percent amount, silver-containing antimicrobial agent (b) when incorporated by itself in silicone rubber (a) in an amount of X+Y weight percent therein and carboxylic acid (c) when incorporated by itself in silicone rubber (a) in an amount of X+Y weight percent therein imparting no significant antimicrobial activity to silicone rubber (a) but in the combination therein of up to X weight percent silver-containing antimicrobial agent (b) and up to Y weight percent carboxylic acid (c) imparting significant antimicrobial activity to silicone rubber (a), such activity being exhibited at the interface of an exposed surface of silicone rubber (a) and a microbe-populated aqueous material in contact therewith.
