Compared to the intended EU reference level of 300 Bq m−3 for indoor radon concentrations, the contribution of building materials appears to be low. Considering the recommended limit of 100 Bq m−3 by WHO, their contribution is supposed to be relevant, especially at low air exchange rates. This study as part of a two-part research project investigated the suitability of direct low level 222Rn measurement under simulated indoor conditions with commercial radon monitors and dynamically operated emission test chambers. Active measuring devices based on ionisation or scintillation chambers with 1-σ uncertainties below 8.6% at 20 Bq m−3 were found to be best suitable for a practical test procedure for the determination of radon exhalation rates of building materials. For the measurement of such low concentrations, the knowledge of the accurate device background level is essential.
The EU FP7 NanoDefine project was launched in November 2013 and will run until October 2017. The Project is dedicated to support the implementation of the EU Recommendation on the Definition of Nanomaterial
by the provision of the required analytical tools and respective guidance. Main goal is to develop a novel
tiered approach consisting of (i) rapid and cost-efficient screening methods and (ii) confirmatory measurement
methods. The "NanoDefiner" eTool will guide potential end-users, such as concerned industries and regulatory bodies as well as enforcement and contract laboratories, to reliably classify if a material is nano or not. To achieve this objective, a comprehensive inter-laboratory evaluation of the performance of current
characterisation techniques, instruments and software is performed. Instruments, software and methods are
further developed. Their capacity to reliably measure the size of particulates in the size range 1-100 nm and
above (according to the EU definition) is validated. Technical reports on project results are published to
reach out to relevant stakeholders, such as policy makers, regulators, industries and the wider scientific community, to present and discuss our goals and results, to ensure a continuous exchange of views,
needs and experiences obtained from different fields of expertise and application, and to finally integrate the resulting feedback into our ongoing work on the size-related classification of nanomaterials.