BfR | Annual Report 2013
60
Research into nanoparticles in textiles
and plastics
Nanomaterials are very small materials which have par-
ticular characteristics due to their small size. Because of
this, they are used in many consumer products. Nano-
silver and nanoclay in particular are nanoparticles which
are frequently used in industry. Nanosilver, for example,
has an antimicrobial effect and therefore prevents un-
pleasant smells in used sports gear. Nanoclay platelets
cause plastics to become more rigid and, as plastic ad-
ditives function as a barrier against gases and liquids.
Thus, nanoclay is often used in food packaging. In order
to anchor the nanoclay platelets in the polymeric material,
quaternary ammonium compounds, which function as a
biocide, are added.
The BfR regularly evaluates the current state of analyt-
ics, toxicology and the regulation of nanomaterials, and
is also involved in a range of research projects in these
areas. Examples include the EU projects NANoREG and
NanoDefine, which aim to develop methods for the regu-
latory testing of nanomaterials and find suitable detection
methods for the implementation of the EU definition. Both
projects started in 2013 and a further project, nanoGEM,
was completed in the same year (see info box).
The BfR also regularly conducts health assessments on
the concrete use of nanoparticles in textiles and plastics.
In its opinion from 2009, for example, the institute refers to
findings indicating adverse effects of nanosilver on living
cells and the risk of increasing resistance. At the moment,
the BfR is investigating whether the consumer comes into
any contact at all with nanosilver from textiles and nano-
clay from food contact materials. Such exposure is not
inevitable; it rather depends on whether nanoparticles
are released from the products and are transferred to the
human body. In order to find out whether particles have
a migration potential, the BfR uses synthetic perspiration
solutions or food simulants. For a comprehensive analysis,
the nanomaterials are first characterised. Electron micro-
scopes, which can detect nanomaterials up to around
100 nanometres and accurately determine the exact size
of the particle, are used for textiles. Plastics are further
identified using infrared spectroscopy. Inductively cou-
pled mass spectrometry then determines which concen-
trations of relevant elements are present in the product
and how much is released into the artificial simulants at
various time intervals.
For textiles, it appears that the type of production technol-
ogy used has a significant influence on the consumer's
exposure to nanosilver. Nanoparticles which are applied
onto the fibres (fibre coating) are released more easily
than those which are worked into the fibre. With polymeric
materials, the release can be controlled through the skil-
ful use of quaternary ammonium compounds which are
fine-tuned to the material and the food to be packaged.
As part of the “
nanoGEM
: nanostructured materi-
als – health, exposure and material properties”
project funded by the Federal Ministry of Education
and Research, the BfR and 19 partner organisa-
tions investigated the potential health risks posed by
nanomaterials. The BfR's task was to systematically
examine several test substances in various biological
settings for their size and interaction with proteins. In
addition, the BfR established methods for examining
modes of action and assessed consumer exposure
to nanomaterials using computer modelling. The
results showed that only a few of the 16 nanomateri-
als exhibited damaging effects. If the surfaces of the
particles were modified, then harmful effects could
be reduced. Furthermore, the use of nanomaterials
in consumer products generally causes no serious
contamination for the consumer. Instead, the risk
posed by specific materials should be investigated
on an individual basis.
>>
The BfR regularly evalu-
ates the current state of
analytics, toxicology and
the regulation of nano-
materials.
