Materials_**2013**, \(6\), 1090-1117; doi:10.3390/ma6031090  
_Materials_  
**ISSN 1996-1944**  
www.mdpi.com/journal/materials  
_Article_  
**Towards a Consensus View on Understanding Nanomaterials Hazards and Managing Exposure: Knowledge Gaps and Recommendations**  
**[PERSON] 1, [PERSON] 2, [PERSON] 3,4, [PERSON] 5, [PERSON] 6, [PERSON] 7, [PERSON] 8,9, [PERSON] 10 and [PERSON] 11-9**  
1 Centre for Bioethics & Emerging Technologies, St Mary's University College, London, TW1 4 SX, UK; E-Mail: [EMAIL_ADDRESS]  
2 Centre for BioNano Interactions, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, UK; E-Mail: [EMAIL_ADDRESS]  
3 National Institute for Public Health and the Environment (RIVM), Bilthoven 3720 BA, The Netherlands; E-Mail: [EMAIL_ADDRESS]  
4 Institute for Risk Assessment Sciences, Utrecht University, NL-3508 TD Utrecht, The Netherlands  
5 Ecotoxicology Research and Innovation Centre, The University of Plymouth, Drake Circus, Plymouth PL4 8 AA, UK; E-Mail: [EMAIL_ADDRESS]  
6 School of Life Sciences, Heriot-Watt University, Edinburgh EH14 4 AS, UK; E-Mail: [EMAIL_ADDRESS]  
7 Institute for Occupational Safety and Health, Deutsche Gesetzliche Unfallversicherung (DGUV), Alte Heerstr 111, Sankt Augustin 53757, Germany; E-Mail: [EMAIL_ADDRESS]  
8 Air Quality & Sustainable Nanotechnology, Institute of Energy and Environmental Technology e.V. (IUTA), D-47229 Duisburg, Germany; E-Mail: [EMAIL_ADDRESS]  
9 Center for Nanointegration Duisburg-Essen (CeNIDE), University Duisburg-Essen, D-47057 Duisburg, Germany  
10 Health Effects Laboratory, Environmental Chemistry Department, NILU-Norwegian Institute for Air Research, Institutveien 18, Kjeller 2027, Norway; E-Mail: [EMAIL_ADDRESS]  
11 Institute for Work and Health, Rte de la Corniche 2, Epalinges-Lausanne CH-1066, Switzerland  
* Author to whom correspondence should be addressed; E-Mail: [EMAIL_ADDRESS]; Tel.: +41-21314-7453; Fax: +41-21314-7430.  
_Received: 11 January 2013; in revised form: 21 February 2013 / Accepted: 28 February 2013 / Published: 20 March 2013_  
**Abstract:** The aim of this article is to present an overview of salient issues of exposure, characterisation and hazard assessment of nanomaterials as they emerged from the consensus-building of experts undertaken within the four year European Commission coordination project NanoImpactNet. The approach adopted is to consolidate and condense the findings and problem-identification in such a way as to identify knowledge-gaps and generate a set of interim recommendations of use to industry, regulators, research bodies and funders. The categories of recommendation arising from the consensual view address: significant gaps in vital factual knowledge of exposure, characterisation and hazards; the development, dissemination and standardisation of appropriate laboratory protocols; address a wide range of technical issues in establishing an adequate risk assessment platform; the more efficient and coordinated gathering of basic data; greater inter-organisational cooperation; regulatory harmonization; the wider use of the life-cycle approaches; and the wider involvement of all stakeholders in the discussion and solution-finding efforts for nanosafety.  
keywords:nanomaterial characterisation; release; exposure; hazard; nanotoxicology; nanosafety; occupational health; consensus building; life cycle approach; monitoring; protocols