This invention pertains to method for imparting a durable antimicrobial activity to substrates, particularly textiles. An acetate-free metal and peroxide antimicrobial treatment formulation is prepared by adjusting the pH of a mixture of a metal salt in aqueous hydrogen peroxide to about 7.5. The substrate is treated with the composition and dried to afford the treated substrate with antimicrobial activity. Zinc salts, ions, or complexes are preferred.