During the aging of products containing nanomaterials, a release of particles can occur.

In the case of textile products, 4 main factors affect the quantity of nanoparticle release, the transformation of the textile in its lifetime [D.M. Mitrano et al., Environmental International 77 (2015) 132-147]:

• the incorporation method into the material (composition of the textile, shape of the nanoparticles, location, adhesion to the matrice),
• use of the textile (temperature, abrasion, sweat),
• cleaning and the related products (detergent, bleach),
• elimination.

Depending on the design of the material and external impacts, nanoparticles can be release in the form of simple particles, agglomerates, embedded in a matrix, and/or as  dissolved ions [C. Lorenz et al., Chemosphere 89 (2012) 817-824 / D.M. Mitrano et al., Environmental International 77 (2015) 132-147 / D.M. Mitrano et al., Environmental Science and Technology 50 (2016) 5790-5799].

As an example, in the case of nanosilver in textiles, a large part will probably release in the wastewater after washing. In the water treatment plant, due to a chemical transformation, the most part of the silver nanoparticles seems to transform into Ag2S, a less toxic specie [C. Levard et al., Environmental Science and Technology 46 (2012) 6900-6914]. Release of particles is less important in the case of skin contact,  biological fluids (sweat,…) or incineration [D.M. Mitrano et al., ACS Nano 8 (2014) 7208-7219 / E. Lombi et al., Chemosphere 111 (2014) 352-358 / N. von Götz et al., Environmental Science and Technologie 47 (2013) 9979-9987].