Over the time of laundering, several scenarios for the transformation of silver ions in washing solutions are possible: (1) oxidation of silver ions into elemental silver, (2) aggregation of elemental silver into aparticle, and (3) complexation of silver ions with detergent components. The decreasing trend by ISE and increasing trend by ICP−MS support the transformation of ionic silver in washing solutions. Above 20 cycles, there were no significant changes in the concentration by the two methods. The internal silver nanoparticles, which were encased within the fiber, stabilized the silver release.