Qualitative and Semiquantitative Assessment of Exposure to Engineered Nanomaterials within the French EpiNano Program: Inter- and Intramethod Reliability Study

The relatively recent development of industries working with nanomaterials has created challenges for exposure assessment. In this article, we propose a relatively simple approach to assessing nanomaterial exposures for the purposes of epidemiological studies of workers in these industries. This method consists of an onsite industrial hygiene visit of facilities carried out individually and a description of workstations where nano-objects and their agglomerates and aggregates (NOAA) are present using a standardized tool, the Onsite technical logbook. To assess its reliability, we implemented this approach for assessing exposure to NOAA in workplaces at seven workstations which synthesize and functionalize carbon nanotubes. The prediction of exposure to NOAA using this method exhibited substantial agreement with that of the reference method, the latter being based on an onsite group visit, an expert’s report and exposure measurements (Cohen kappa = 0.70, sensitivity = 0.88, specificity = 0.92). Intramethod comparison of results for exposure prediction showed moderate agreement between the three evaluators (two program team evaluators and one external evaluator) (weighted Fleiss kappa = 0.60, P = 0.003). Interevaluator reliability of the semiquantitative exposure characterization results was excellent between the two evaluators from the program team (Spearman rho = 0.93, P = 0.03) and fair when these two evaluators’ results were compared with the external evaluator’s results. The project was undertaken within the framework of the French epidemiological surveillance program EpiNano. This study allowed a first reliability assessment of the EpiNano method. However, to further validate this method a comparison with robust quantitative exposure measurement data is necessary

Synthetic Amorphous Silicon Dioxide (NM-200, NM-201, NM-202, NM-203, NM-204): Characterisation and Physico-Chemical Properties

The European Commission's Joint Research Centre (JRC) provides scientific support to European Union policy including nanotechnology. Within this context, the JRC launched, in February 2011, a repository for Representative Test Materials (RTMs), based on preparatory work started in 2008. It supports both EU and international research projects, and especially the OECD Working Party on Manufactured Nanomaterials (WPMN). The WPMN leads an exploratory testing programme "Testing a Representative set of Manufactured Nanomaterials" for the development and collection of data on characterisation, toxicological and ecotoxicological properties, as well as risk assessment and safety evaluation of nanomaterials. The purpose is to understand the applicability of the OECD Test Guidelines for the testing of nanomaterials as well as end-points relevant for such materials. The Repository responds to a need for nanosafety research purposes: availability of nanomaterial from a single production batch to enhance the comparability of results between different research laboratories and projects. The availability of representative nanomaterials to the international scientific community furthermore enhances and enables development of safe materials and products. The present report presents the physico-chemical characterisation of the synthetic amorphous silicon dioxide (SiO2, SAS) from the JRC repository: NM-200, NM-201, NM-202, NM-203 and NM-204. NM-200 was selected as principal material for the OECD test programme "Testing a representative set of manufactured nanomaterials". NM-200, NM-201 and NM-204 (precipitated SAS) are produced via the precipitation process, whereas NM-202 and NM-203 (fumed or pyrogenic SAS) are produced via a high temperature process. Each of these NMs originates from one respective batch of commercially manufactured SAS. They are nanostructured, i.e. they consist of aggregated primary particles. The SAS NMs may be used as a representative material in the measurement and testing with regard to hazard identification, risk and exposure assessment studies. The results for more than 15 endpoints are addressed in the present report, including physical-chemical properties, such as size and size distribution, crystallite size and electron microscopy images. Sample and test item preparation procedures are addressed. The results are based on studies by several European laboratories participating to the NANOGENOTOX Joint Action, as well as the JRC.JRC.I.4-Nanobioscience

Multi-walled Carbon Nanotubes, NM-400, NM-401, NM-402, NM-403: Characterisation and Physico-Chemical Properties

In 2011 the JRC launched a Repository for Representative Test Materials that supports both EU and international research projects, and especially the OECD Working Party on Manufactured Nanomaterials' (WPMN) exploratory testing programme "Testing a Representative set of Manufactured Nanomaterials" for the development and collection of data on characterisation, toxicological and ecotoxicological properties, as well as risk assessment and safety evaluation of nanomaterials. The JRC Repository responds to a need for availability of nanomaterial from a single production batch to enhance the comparability of results between different research laboratories and projects. The present report presents the physico-chemical characterisation of the multi-walled carbon nanotubes (MWCNT) from the JRC Repository: NM-400, NM-401, NM-402 and NM-403. NM-400 was selected as principal material for the OECD WPMN testing programme. They are produced by catalytic chemical vapour deposition. Each of these NMs originates from one respective batch of commercially manufactured MWCNT. They are nanostructured, i.e. they consist of more than one graphene layer stacked on each other and rolled together as concentric tubes. The MWCNT NMs may be used as a representative material in the measurement and testing with regard to hazard identification, risk and exposure assessment studies. The results are based on studies by several European laboratories participating to the NANOGENOTOX Joint Action.JRC.I.4-Nanobioscience

Titanium Dioxide, NM-100, NM-101, NM-102, NM-103, NM-104, NM-105: Characterisation and Physico-Chemical Properties

The European Commission's Joint Research Centre (JRC) provides scientific support to European Union policy including nanotechnology. Within this context, the JRC launched, in February 2011, a repository for Representative Test Materials (RTMs), based on preparatory work started in 2008. It supports both EU and international research projects, and especially the OECD Working Party on Manufactured Nanomaterials (WPMN). The WPMN leads an exploratory testing programme "Testing a Representative set of Manufactured Nanomaterials" for the development and collection of data on characterisation, toxicological and ecotoxicological properties, as well as risk assessment and safety evaluation of nanomaterials. The purpose is to understand the applicability of the OECD Test Guidelines for the testing of nanomaterials as well as end-points relevant for such materials. The Repository responds to a need for nanosafety research purposes: availability of nanomaterial from a single production batch to enhance the comparability of results between different research laboratories and projects. The availability of representative nanomaterials to the international scientific community furthermore enhances and enables development of safe materials and products. The present report presents the physico-chemical characterisation of the Titanium dioxide series from the JRC repository: NM-100, NM-101, NM-102, NM-103, NM-104 and NM-105. NM-105 was selected as principal material for the OECD test programme "Testing a representative set of manufactured nanomaterials". NM-100 is included in the series as a bulk comparator. Each of these NMs originates from one batch of commercially manufactured TiO2. The TiO2 NMs may be used as representative material in the measurement and testing with regard to hazard identification, risk and exposure assessment studies. The results for more than 15 endpoints are addressed in the present report, including physico-chemical properties, such as size and size distribution, crystallite size and electron microscopy images. Sample and test item preparation procedures are addressed. The results are based on studies by several European laboratories participating to the NANOGENOTOX Joint Action, as well as by the JRC.JRC.I.4-Nanobioscience

Dispositif de contrôle des compteurs (DCC). Développement, qualification et mise en place d'une procédure opérationnelle.

Les stratégies de mesure des expositions professionnelles aux aérosols de nanomatériaux mettent en avant l’utilisation de techniques de mesure de la concentration en nombre de particules ainsi que leur distribution granulométrique. L’objectif de ces travaux était de mettre en place un système de référence permettant de mener en laboratoire des campagnes de vérification de compteurs de noyaux de condensation (CNC). Pour cela, le dispositif Calibration Tool développé initialement par l’ITEM Fraunhofer a été acquis par le laboratoire de Métrologie des aérosols de l’INRS. La caractérisation de ce système a fait l’objet d’une étude paramétrique. Utilisé en association à un compteur de référence, cet équipement peut désormais être utilisé en routine suivant la procédure élaborée, l'ensemble étant dénommé DCC pour dispositif de contrôle des compteurs. Enfin, la mise en œuvre du DCC a été réalisée sur 9 modèles de CNC portables dédiés à la mesure de la concentration en nombre de particules en atmosphère de travail

Determining the count median diameter of nanoaerosols by simultaneously measuring their number and lung deposited surface area concentrations

International audienceDue to the increasing use of nanomaterials in research and product development, it is probable that the number of situations of occupational exposure to them is also rising. The same is true for the number of workers. Although current research in nanotoxicology is far from conclusive, it is clear that relying on mass concentration and chemical composition alone is not appropriate in all cases and alternative measurement methods and approaches need to be developed. In this work, we propose a method based on simultaneous size-integrated measurements of two particle concentrations (number and lung-deposited surface area, CNC/NSAM), and on the estimation of the average size of potentially inhaled particles from the combination of these measurements. The proposed method could be part of a measurement strategy that is practical as it would use field-portable, commercially available aerosol instruments. In the absence of instruments providing real-time sizeresolved measurements, this original approach can be carried out as considering that the ratio of these concentrations is a monotonous function of particle size. Indeed, the latter function depends only on the geometric standard deviation of airborne particle number size distribution, assumed to be lognormal. Compared to SMPS data for polydisperse aerosols having three chemical natures with count median diameters ranging from 64 to 177 nm, experimental results were obtained with acceptable relative discrepancies of ±30%. Though the method proposed is less accurate than traditional instruments like SMPS, it can be used for workplace air monitoring or as a screening tool to detect the presence of airborne nanoparticles

Evaluating three direct-reading instruments based on diffusion charging to measure surface area concentrations in polydisperse nanoaerosols in molecular and transition regimes

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Characterizing surface-area of airborne nanostructured particles

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Concevoir la prévention d’un risque émergent : une démarche fondée sur les représentations et les activités

International audienceThe emergence of nanomaterials is producing major technological innovations in many business sectors. There are major scientific and economic issues concerning these new materials which give rise to important health and environmental questions. This article describes the ergonomic intervention carried out in an industrial company that was seeking to collectively construct a risk prevention approach to nanomaterials. The goal of this study was to understand the real prevention practices that were implemented to counter this emerging risk and explore the risk representations of the workers in connection with their work activities. The study also looked at how the mobilization of company stakeholders around the prevention approach and their experiences with work activities transformed their representations and created a debate about the rules, procedures, and guidelines to be established.L’émergence des nanomatériaux constitue aujourd’hui une innovation technologique majeure dans tous les secteurs d’activité. Ces nouveaux matériaux représentent des enjeux scientifiques et économiques importants et posent des questions quant à leurs effets sur la santé et sur l’environnement. Cet article décrit l’intervention ergonomique réalisée dans une entreprise du secteur industriel qui vise la construction collective d’une démarche de prévention des risques liés aux nanomatériaux. Il s’agit de comprendre les pratiques réelles de prévention mises en œuvre par rapport à ce risque émergent, en explorant les représentations du risque des salariés en lien avec leurs activités de travail. Il s’agit aussi d’explorer comment la mobilisation des acteurs de l’entreprise autour du dispositif de prévention et leur confrontation à l’action et à l’activité de travail transforment leurs représentations et créent du débat sur la prescription à construire