Case Study Challenges in Human Health Hazard and Risk Assessment of Nanoscale Silver - Safety of Nanomaterials along Their Lifecycle - page 415

19 Case Study

Challenges in Human Health
Hazard and Risk Assessment
of Nanoscale Silver

Christian Riebeling and Carsten Kneuer

CONTENTS
19.1 Background ................................................................................................... 417
19.2 Introduction .................................................................................................. 418
19.3 Use(s) and Potential Sources of Nanosilver Exposure .................................. 419
19.4 Nanomaterial Identification .......................................................................... 422
19.5 Transformation (Speciation) of Nanosilver Material along Its Lifecycle ..... 425
19.6 Hazard Identification and Characterization .................................................. 426
19.7 Challenges Caused by Limitations in Nanoparticle Measurement
Techniques .................................................................................................... 430
References .............................................................................................................. 431

19.1 BACKGROUND
Several types of nanomaterials are currently subject to discussion of potential health
hazards and risks associated with their use, and corresponding testing programs
have been initiated (e.g., OECD 2010). Silver nanoparticles might have found their
way into the largest number of practical applications including consumer products.
For the 1,628 products claiming to employ nanotechnology that are listed in the on-
line inventory of the Woodrow Wilson International Center for Scholars (WWICS)
Project on Emerging Nanotechnologies (PEN) (WWICS 2013), the most often iden-
tified nanomaterial is silver. Twenty-four percent, or a total of 383 products suppos-
edly contained nanosilver (WWICS 2013a). Furthermore, often employed materials
include titanium/titanium dioxide in 179 products, carbon in 87 products, silicon
dioxide in 52 products, zinc/zinc oxide in 36 products, and gold in 19 products.
This inventory is the most comprehensive, freely accessible database to date. It lists
products available to consumers, which claim to employ nanotechnology, many of
which do not identify a nanomaterial. On the German site www.nanowatch.de of the

417