12 August 2011
2. Back ground of the project and choice of nanomaterials tested
The nanomaterials to be tested titanium dioxide (TiO2), silicon dioxide (SiO2) and carbon nanotubes (CNTs) were chosen on the basis of their relevance in the scientific and public debate, they are widely used in many consumer products.
The OECD WPMN (Working Party on Manufactured Nanomaterials) published a list of representative MNs (188KB) for testing. It concerns MNs which are already or soon to be commercialised and with widespread use. TiO2 and SiO2 were entered on the list because of their high production tonnage and their use in many everyday consumer products. Currently, many uncertainties remain concerning the nanometric forms; risks are, at the moment, assessed using the tools developed for standard chemicals. The Joint Action ( JA) will strive to develop a consolidated assessment methodology for assessing the genotoxic hazards of these materials, selecting the major usages such as additives to food and rubber for SiO2 and cosmetics and food for TiO2. Even for these well known MNs, additional testing is necessary, applying new and appropriate test methods adapted to nanomaterials.
In the case of carbon nanotubes, which according to the literature might present toxicological effects in animal experiments similar to asbestos, there are important knowledge gaps, and therefore different usages will be tested. For those reasons, four (4) different silicon dioxide MNs will be tested, obtained from the two different production methods (precipitated/pyrogenic). Five (5) different titanium dioxides will be tested, including both main crystal phases (rutile/anatase), and with different biochemical properties (hydrophylic/hydrophobic). Six (6) carbon nanotubes available on the market, which have different physico-chemical characteristics such as different length and diameters, and originate from different production processes will be tested.
This work will be complementary to the OECD sponsorship programme for testing of MNs (658 KB). For the JA, the products were kindly provided by the manufacturers. They were all sub-sampled and shipped to the participating laboratories by the Joint Research Centre. The same batch of MNs will be used for the testing in both programmes.Last Updated on Friday, 16 September 2011 14:22