Session 2: Lessons learned and testing
National Research Centre for the Working Environment (NRCWE)
ABSTRACT CONTENT / DETAILS:
There is an urgent need to identify suitable methods and standard operation procedures for reliable characterization of manufactured nanomaterials (MN) and the exposure characteristics in toxicological testing.
Specific need of methods for MN size-distribution of the primary nano-objects and specific surface area (SSA) measurement has been sparked by the EU regulatory definition of a MN, which has moved the measurement paradigm from mass- to number-weighed size-distribution of the minimum dimensions of nano-objects and the volume-SSA.
At the same time, the variability in toxicological test results increases with the growing number of toxicological studies. This may in part be caused by the many different procedures for nanomaterial dispersion in both dry and liquid state, use of different exposure media, and lack of harmonized exposure characterization.
Numerous data has been generated on a specific suite of OECD test materials in several national and EU-funded research projects. These projects included a.o. the EU-FP7 projects ENPRA, the EAHC-project NANOGENOTOX, and the DEFRA-project PROsPECT besides the so-called sponsorship program in the OECD Working Party on Manufactured Nanomaterials.
So far the results have shown that sometimes specific characterization end-points considered straight-forward such as quantification of chemical composition and surface coatings cause the greatest challenges and vice-versa where a method for determination of the number-weighed size-distribution of pure NM appears within reach already.
The presentation will include a discussion on the lessons learned from these previous projects and the attempt to test and characterize NM following a highly harmonized top-down designed approach in the EU FP7 project NANoREG.