We have previously reported on a study by Arizona State researchers looking into the potential release of nanosilver particles from odor-killing socks during theoretical wash cycles.  A new study from Switzerland examines the issue in further detail.

L. Geranio, et al., "The Behavior of Silver Nanotextiles during Washing," Environ. Sci. Technol. (Sept. 2009).

Three authors from the Swiss Federal Laboratories for Materials Testing and Research conducted the study with the aim of determining "the amount and the form of Ag released during washing from nine fabrics with different ways of silver incorporation into or onto the fibers."  The study generally found that when washed at low pH levels, there was little dissolution of nanoparticles from the textiles being tested.  However, the researchers theorized that the use of bleach "can greatly accelerate the dissolution of Ag."  The percentage of total silver emitted during one wash cycle for the fabrics varied between 1% and 45%.  Almost 75% of the silver released was greater than 450 nm in diameter.