A method for treating laundry is provided. The method includes steps of applying a bleaching and antimicrobial composition to laundry in a laundry washing machine at a first pH that favors bleaching properties and at a second pH that favors antimicrobial properties, wherein the first pH and the second pH are different, and draining the bleaching and antimicrobial composition from the laundry. The step of applying a bleaching and antimicrobial composition to laundry can include a step of washing the laundry with a detergent composition for the removal of soil. In addition, the step of applying a bleaching and antimicrobial composition to laundry can precede or follow a step of washing laundry with a detergent composition for the removal of soil. A bleaching and antimicrobial composition and a laundry washing machine are provided.