Risk Assessment of Manufactured Nanomaterials - Environmental and Human Health Impacts of Nanotechnology - page 395

Table 10.3 Possible testing strategies for new particles.

1 Preliminary
assessment

• physical, chemical data
• particle size characterisation

2 In vitro studies • macrophages and epithelial cells

• test for cell toxicity (cell membrane, impaired electron transport)
• test for migratory ability, phagocytosis and release of infl amma-
tory mediators

3 Short-term In vitro
studies

• comparison to 'benchmark' particles
• inhalation studies of 1-5 days
• analysis of bronchioalveolar lavage (BAL) fl uid for cells and
infl ammatory markers
• histopathology
4 Medium-term studies • if indicated from 3 above
• up to 90 days with similar parameters
• includes 2-3 month recovery period

5 Long-term studies • if indicated from 4 above

• all above end-points plus cancer

limits or other registration triggers (NIA, 2007; discussed in more detail in Appendix
10.A). There are no specifi c regulatory requirements for nanomaterials under
REACH, although substances need to be risk assessed in the form in which they
are placed on the market. This will include nanomaterials defi ned as existing sub-
stances (present on the EU EINECS chemicals database), with registration dead-
lines depending on the volume of production of the substance.
Concern has been raised that nanomaterials made of the same material as an
existing bulk chemical may escape appropriate triggers for risk assessment. This
could be resolved by adding an extra trigger to the hazard evaluation that would
require evidence that the nanomaterial has the same chemical or biological proper-
ties as the bulk compound (Crane and Handy, 2007; Crane et al. , 2008 ). If the
materials behave in the same way, this could be treated as an existing material (i.e.
already considered under REACH) from the viewpoint of hazard. Alternatively,
if the nanomaterial showed some differences from the existing bulk substance, this
would trigger a full risk assessment as if it was a previously unregistered chemical
and subject to REACH registration as described above.
On 17 June 2008, the European Commission issued a communication on the
regulatory aspects of nanomaterials stating, 'Nanotechnologies are enabling tech-
nologies, with high potential benefi ts for consumers, workers, patients, and the
environment, as well as the creation of jobs. On the other hand, nanotechnologies
and nanomaterials may expose humans and the environment to new risks, possibly
involving quite different mechanisms of interference with the physiology of human
and environmental species' (ECC, 2008). Overall, it can be concluded that current
legislation covers, to a large extent, the relative risks of nanomaterials and that the
risks can be dealt with under the current regulatory framework. However, current
legislation may have to be modifi ed in the light of new information becoming avail-