Emissions from Consumer Products Containing Engineered Nanomaterials over Their Lifecycle - Safety of Nanomaterials along Their Lifecycle - page 338

16

Washing Sweat Saliva

14

12

10

8

6

4

2

0

bdl <1 2-10

Release [%]

11-50 >51

FIGURE 15.3 Percent of the total Ag released from nano-textiles. (Data extracted from
Benn, T.M., Westerhoff, P. Environ. Sci. Technol., 42, 4133-4139, 2008; Geranio, L. et al.,
Environ. Sci. Technol., 43, 8113-8118, 2009 GSM, 8, 2009; Benn, T. et al. J. Environ.
Quality, 39, 1875-1882, 2010; Kulthong, K. et al., Part Fibre Toxicol. 7, 8, 2010; DEPA
(2012), Assessment of nanosilver in textiles on the Danish market, Environmental Project No.
1432, Copenhagen, Danish Environmental Protection Agency; KEMI (2012), Antibacterial
substances leaking out with the washing water: analyses of silver, triclosan and triclocarban
in textiles before and after washing, Sundbyberg, Swedish Chemicals Agency; Lorenz, C.
et al., Chemosphere 89, 817-824, 2012.)

fraction and that the fraction >0.45 µm was the most important one. The dissolved
fraction was for most textiles only of very minor importance. The fraction >0.45 µm,
which includes the nanoparticulate fraction, was 75%-100% for the various tex-
tiles (except for one textile where it was only 40%) (Geranio et al. 2009), indicating
that only a small fraction of the silver is released as single dispersed nanoparticles.
Electron microscopy investigations revealed that AgCl was the most often observed
form of Ag in the washing solution, Figure 15.4 (Lorenz et al. 2012).
Because textiles are in direct contact with the human skin several authors have
also studied the release of Ag into sweat (Kulthong et al. 2010; Yan et al. 2012).
One study targeted the release of Ag from the washing machine itself, using a com-
mercially available washing machine that supplies Ag to the wash water during the wash
cycle (Farkas et al. 2011). The washing machine released silver into the washing solution
with an average concentration of 11 μg/L. Less than 2% of this Ag was in the dissolved
form. The presence of Ag nanoparticles was confirmed by a single particle ICP-MS, an
average size of 10 nm was measured with a transmission electron microscopy.
Cleveland et al. (2012) exposed different Ag textiles to an estuarine mesocosm
(with a salinity of 20%), mimicking release from textiles that are disposed of directly
in the environment. After 60 days of exposure about 95% of the total silver content
of the sock had been released. The wound dressing had even lost 99% of the silver
content, the toy bear 82%.