Papers by Olivier Witschger
Environmental, Health and Safety Impacts of Nanoparticles n°15, September 2014
Nanoparticules, nanomateriaux: Effets sur la sante et l'Environnement n°02, Fevrier 2008
Methods for Testing Dustiness
Nanomaterial Characterization
Toward a Better Assessment of Occupational Exposure to Nanoparticles Taking into Account Work Activities
Advances in Intelligent Systems and Computing
Numerous industrial sectors and processes may cause worker exposure to ultrafine particles or eng... more Numerous industrial sectors and processes may cause worker exposure to ultrafine particles or engineered nanoparticles (NPs). These exposures may affect workers’ health if control measures (organisational, engineering, PPE…) are not properly defined, used and maintained. Today the available exposure data are insufficient for epidemiological studies. Part of the reason for this lack of data may be found in the variety of approaches used to assess worker exposure.
En plus de la composition chimique, la taille des particules et la concentration sont parmi les p... more En plus de la composition chimique, la taille des particules et la concentration sont parmi les principaux parametres utilises pour caracteriser l'exposition aux nanoparticules dispersees dans l'air. Pour evaluer les expositions professionnelles, l'utilisation d’instruments de mesure en temps reel sont recommandes dans les strategies recentes publiees. Parmi les dispositifs portables individuels permettant d’evaluer l'exposition aux aerosols de nanoparticules en milieu de travail, le DiSCmini (Matter Aerosol AG, Suisse) a ete identifie comme un candidat potentiel. Cet appareil permet de mesurer la concentration de nanoparticules dans l'air et la taille moyenne des particules avec une bonne resolution temporelle. Des nanoaerosols de test monodisperses et polydisperses, de composition chimique et de morphologie variables, ont ete produits en laboratoire en utilisant l'installation CAIMAN, couvrant une gamme de tailles de particules entre 15 et 400 nm et de conc...
En 2004, plusieurs experts reunis par la Commission Europeenne estimaient par consensus que les r... more En 2004, plusieurs experts reunis par la Commission Europeenne estimaient par consensus que les risques potentiels des nanomateriaux manufactures ne pouvaient etre predits ou derives des proprietes connues de la meme matiere sous une forme plus grossiere. Selon leur estimation, fabriquer un nanomateriau revenait a creer un nouvel agent chimique different de l’agent chimique originel et un numero d’identification specifique (CAS) etait necessaire. La mise en œuvre d’une telle decision aurait permis d’initier des mesures incluant la determination de valeurs limites d’exposition professionnelle (VLEP). En 2005, l’INRS avait egalement rapporte la necessite de reevaluer les VLEP des poussieres totales et alveolaires, estimant qu’une reflexion relative aux particules ultrafines devrait par ailleurs etre entreprise, en raison de leurs proprietes toxicologiques particulieres. Depuis, en France du moins, aucune valeur limite d’exposition professionnelle relative aux nanomateriaux manufacture...
French approach for characterizing potential emissions and exposure to aerosols released from nanomaterials in workplace operations
There are a number of occupational situations where potential for emission and exposure to nanoma... more There are a number of occupational situations where potential for emission and exposure to nanomaterials exist along the complete life cycle of the nanomaterials, i.e. research, synthesis, downstream use, application or treatment of products, and waste recycling/disposal. While research continues to address questions of nanomaterials toxicity, there is a need to gain a better understanding of actual workplace exposures, practices, and also determine the effectiveness of existing control measures in reducing exposures that are in place. These field studies are of particular importance as workers, whose number is growing, are the first people in society that are exposed. Various strategies have been proposed worldwide to assess workplace exposure (BSI, 2010; Consent German Report, 2011; Methner et al. 2010; Ramachandran et al., 2011), but so far, no definite standardized international method is available. In that context, a working group was established in 2010 in France with CEA, INR...
Nanomaterials Definitions , toxicological risk , characterisation of occupational exposure and prevention measures
Coupelle d’echantillonnage de particules microbiologiques en suspension dans une atmosphere et dispositif d’echantillonnage pourvu d’une telle coupelle
Coupelle d'echantillonnage de particules microbiologiques en suspension dans une atmosphere e... more Coupelle d'echantillonnage de particules microbiologiques en suspension dans une atmosphere et dispositif portatif d'echantillonnage pourvu d'une telle coupelle Cette coupelle d'echantillonnage de particules en suspension dans une atmosphere comprend un corps de coupelle rotatif muni d'un fond (30) et d'une paroi peripherique (32) generalement cylindrique s'etendant a partir dudit fond et delimitant avec ce fond un volume rempli d'un milieu de piegeage des particules de la suspension. Le corps de la coupelle comporte en outre une couronne (34) fermant partiellement la tranche d'extremite de la paroi peripherique du corps et delimitant un passage (36) pour les particules, la couronne etant pourvue de canaux (38) s'etendant de maniere radialement externe en direction de la peripherie du corps et adaptee pour engendrer, lors de la rotation du corps dans un carter, un flux d'air vers le milieu de reception emplissant le corps a travers ledit p...
Historiquement, l’IRSN a développé un savoir-faire en physique et en métrologie des aérosols renc... more Historiquement, l’IRSN a développé un savoir-faire en physique et en métrologie des aérosols rencontrés dans l’industrie nucléaire ; il concerne en particulier les nanoparticules dans le cadre de la radioprotection des mineurs d’uranium [Boulaud et al., 2005]. Les premiers travaux ont porté sur la caractérisation des particules ultrafines radioactives inhalées par cette population, puis les compétences acquises ont été utilisées dans d’autres domaines, comme ceux de la pollution atmosphérique, de la sûreté des installations et des transferts de contamination aux postes de travail et dans l’environnement. Aujourd’hui, ce savoir-faire permet à l’IRSN de mener des études et des recherches avec différents partenaires, qui s’inscrivent dans l’évaluation des risques liés aux nanoparticules. L’Institut contribue à la réponse aux attentes de la société sur ces risques en participant, par exemple, à l’Observatoire des micro et nanotechnologies (OMNT) et à la rédaction d’un ouvrage sur les na...
Workplace exposure to nanomaterials
Recommendations for characterizing potential emissions and exposure to aerosols released from nanomaterials in workplace operations, report of French Working Group
Nanomaterials are increasingly being synthesized and used in the research and in several industry... more Nanomaterials are increasingly being synthesized and used in the research and in several industry sectors. Products that contain embedded nanomaterials are also becoming more commonplace. Potential emissions and exposure to nanomaterials can occur during synthesis, downstream use, application or treatment of products, and waste recycling/disposal. While research continues to address questions of nanomaterials toxicity, more field studies that include aerosol measurements are performed to help determine worker exposures. Among the key factors that will make data from these studies useful for risk assessments or epidemiology in the future is a harmonized measurement strategy. In that context, INRS together with INERIS and CEA (both involved in a national action plan nano-INNOV) established a working group, whose the outcome is a report describing a suggested approach to characterize emissions and inhalation exposures to aerosols where nanomaterials are processed or used during workpla...
Nanoscale Advances
We demonstrate the relevance of the Volume Specific Surface Area to identify nanopowder mixes bas... more We demonstrate the relevance of the Volume Specific Surface Area to identify nanopowder mixes based on either spherical constituent particles with bimodal size distributions, or fiber-like constituent particles with unimodal size distributions.
What does ergonomics have to do with nanotechnologies? A case study
Applied Ergonomics
Journal of Physics: Conference Series
This study aim is to compare the number concentration of airborne nanoparticles reported by 13 di... more This study aim is to compare the number concentration of airborne nanoparticles reported by 13 different Condensation Particle Counters (CPC) with regards to a reference CPC, for a set of aerosols of interest. Among the models investigated, 5 are handheld CPC, while the 8 others are stationary CPC. The latter include butanol-based CPC as well as water-based CPC. Polydisperse test aerosols with modal diameters between 6 and 460 nm were produced in the CAIMAN experimental facility. Non-hydrophobic aerosols consisted of metal-based particles (Ti, C, Al, Cu, Ag), as well as nebulized suspensions (SiO2). Hydrophobic particles consisted of DEHS as well as alkanes (n-C13 to n-C20). Overall, about 400 different conditions were investigated to represent a wide range of aerosols potentially encountered in workplaces. The range of number concentrations provided by the reference CPC was 500 – 400 000 cm−3. To highlight the possible effect of particle counting efficiency on the total concentrati...
Nanoscale Advances
Nanoparticulate powders are increasingly found in the workplace. Inhalation exposure to airborne ... more Nanoparticulate powders are increasingly found in the workplace. Inhalation exposure to airborne nanoparticles (NPs) is possible throughout the life-cycle of the powders. As the toxicity of NPs has never been...
Environmental Science: Nano
This work shows that the volume specific surface area could be a reliable criterion for nanomater... more This work shows that the volume specific surface area could be a reliable criterion for nanomaterial identification.
Journal of Physics: Conference Series
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licenc... more Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Journal of Physics: Conference Series
The aim of this experimental study was to investigate the performance of both portable and transp... more The aim of this experimental study was to investigate the performance of both portable and transportable devices devoted to the real-time measurement of airborne particle number concentration and size (distribution). Electrical mobility spectrometers (SMPS, FMPS, Nanoscan) as well as diffusion chargers (DiSCmini, Nanotracer) were studied. Both monodisperse and polydisperse aerosols were produced within the CAIMAN facility to challenge the instruments. The monodisperse test aerosols were selected in the 15-400 nm diameter range using a differential mobility analyser (DMA), and presented number concentrations of between 6.10 2 and 2.10 5 cm-3. The polydisperse test aerosols presented modal diameters of between 8 and 270 nm and number concentrations between 4.10 3 to 10 6 cm-3. The behavior of the different devices is expressed as (1) the ratio of the reported diameter to the reference diameter, and (2) the ratio of the reported number concentration to the reference concentration. These results are displayed as boxplots to better represent the statistical distribution of the experimental results. For the group of electrical mobility spectrometers, a good agreement between SMPS and FMPS and the reference was demonstrated. A slight tendency for the Nanoscan to underestimate particle size distribution for particles above around 100 nm was observed. The data reported for the group of diffusion chargers demonstrate that all, except the Nanotracer, show a tendency to underestimate particle diameter, by a factor around-40% to-10%. In the case of particle concentration, larger deviations were observed.
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Papers by Olivier Witschger