Table of contents

This volume contains a collection of contributions presented at the 5^th Nanosafe International Conference on Health and Safety issues related to nanomaterials for a socially responsible approach (NANOSAFE 2016) held in Grenoble, France, from 7^th to 10^th November 2016.

Nano objects represent a powerful "enabling technology" leading to revolutionary breakthroughs in many different areas vital for humanity including medicine, energy, environment, etc. and also preserving the rare mineral resources by rendering mater more efficient.

For one of the first time in the science history, risks have been taken into account since the very beginning of the manufactured nanomaterials and Nanosafety is now considered as a specific new scientific area, gaining in importance and maturity each days thanks to our dynamic community spread all over the world.

Following the successful outcome of the four past international conferences on Safe Production and Use of Nanomaterials: Nanosafe 2008, 2010, 2012 and 2014, the Platform Nano Safety "PNS" welcomed the attendees to Minatec, Grenoble, for this fifth edition with some of the most famous specialists in the field.

In 2016, the subtitle of the conference had been slightly changed to "Health and Safety Issues Related to Nanomaterials" in order to welcome inboard two new topics: Urban Nanoparticles and some aspect of Nanomedicine, in addition to the usual issues addressed in previous Nanosafe conferences such as Detection and Characterization, Expology, Release from Nano-enabled Products, Safer by Design Nanomaterials and Process, Risk Management, Nanoproducts to waste, Toxicology, Environmental Interactions, Regulation and Standardization and Nano Responsible Development.

Furthermore, three 3 round tables had been organized in order to promote friendly discussions between attendees: Nano-Responsible Development, Urban Particles Mitigation: What is Reasonably Possible, Nanomedecine: Benefice/Risk.

In this 5^th edition, there were more than 350 registered participants from 29 different countries including 170 oral presentations and 91 posters covering the whole Nanosafety issues in 6 main sessions, satellite workshops and round tables.

This fifth edition had been a great success and the Local Organizing Committee want to acknowledge all the attendees for their presence and the quality of their presentations.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

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 6.10² and 2.10⁵ cm⁻³. The polydisperse test aerosols presented modal diameters of between 8 and 270 nm and number concentrations between 4.10³ to 10⁶ 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.

Strategies for measuring occupational exposure to aerosols composed of nanoparticles and/or ultrafine particles highlight the use of techniques for determining airborne-particle number concentration as well as number size distribution. The objective of the present work was to set up a system for conducting laboratory verification campaigns of condensation particle counters (CPCs). Providing intercomparison data as well as calibrating and checking CPCs are among the key elements in ensuring reliable laboratory or field measurement campaigns. For this purpose, the reproducible aerosol source "Calibration Tool", initially developed by the Fraunhofer ITEM, was acquired by the Laboratory of Aerosol Metrology at INRS. As a first part of this study, a detailed characterization of the Calibration Tool developed at the laboratory is the subject of the parametric study presented here. The complete installation is named the "DCC" for "Device for Counter Check". Used in combination with a reference counter, the DCC can now be used for routine laboratory measurements. Unlike that used for primary calibration of a CPC, the proposed protocol allows a wide range of number concentrations and particle sizes to be investigated and reproduced. The second part of this work involves comparison of the number concentrations measured by several models of CPC in parallel at the exit of a flow splitter, with respect to a reference.

Nanotechnology is a scientific revolution that the food industry has experienced over the last years. Widely employed as food additives and/or food contact materials in consumer products, silver nanoparticles are an example of this innovation. However, their increasing use makes also likely the human ingestion, thus requiring a proper risk analysis. In this framework, a comprehensive characterization of biotransformation of silver nanoparticles in biological fluids is fundamental for the regulatory needs. Herein, we aimed at studying the dissolution behaviour of silver nanoparticles using an in vitro test, which simulates the human oral ingestion of NPs during their passage through the gastrointestinal tract. The nanoparticle suspensions were characterized in the different digestion phases using several techniques to follow the changes of key physical properties (e.g., size, surface charge and plasmon peak) and to quantify the biotransformed products arisen by the process, as for example free silver ions.

Understanding the world of nanoparticles, especially their interactions with the environment, begins with their correct detection and successive quantification. To achieve this purpose, one needs to perform correctly developed standard operating procedures (SOPs). Furthermore, the study of nanoparticles frequently requires their characterisation in complex media (e.g. in cosmetic formulations). In this study, a set of sample preparation procedures for the detection and extraction of NMs in emulsion-based formulations is proposed and their performance for model and real-life products is discussed. A separation or extraction of lipid phases is achieved by means of organic solvents. The polarity of the lipid phases is decisive for selecting an optimum solvent. The use of the Hansen Solubility Parameters (HSP) may clearly support this decision.

The handling of carbon nanotube (CNT) powders is a plausible scenario during the course of the CNT life-cycle. However, related exposure data remain limited. In this context, information about the dustiness of CNT is therefore of great interest, for example for control banding or exposure modelling. Here, we investigate the dustiness of fourteen CNT powders using the Vortex Shaker (VS) method. The central component of the VS method is a stainless steel cylindrical tube, continuously shaken in a circular orbital motion, in which a small volume (0.5 cm³) of the powder to be tested is placed. All samples were obtained through the NANoREG Nanomaterials Information and Web-Order system. The test procedure that we have developed is based on four principal components: (i) a respirable cyclone for gravimetric sampling, (ii) a CPC as a reference instrument for number concentration measurement, (iii) an MPS for collection of particles for EM observations/analysis, and (iv) an ELPI for size-resolved aerosol measurement. In this paper, the data were evaluated using two parameters: (i) the mass-based dustiness index in the respirable fraction; and (ii) the number-based dustiness index in the respirable fraction. The results indicate that the method leads to relatively accurate mass- and number-based dustiness indices. The indices obtained span wide ranges, of 2 and 3 orders of magnitude variation for mass and number respectively, suggesting a corresponding significant difference in terms of potential exposure. EM observations reveal that airborne CNTs are mostly released as bundles of different shapes ranging from a few tens of nanometers up to tens of micrometers in size.

A novel sampler, the NANOBADGE, has been developed to assess personal exposure to nano-objects, agglomerates and aggregates (NOAA) at the workplace. The NANOBADGE collects particles on filters subsequently analyzed by X-Ray Fluorescence spectroscopy (XRF), which provides a mass-based quantification with chemical selectivity. The NANOBADGE was benchmarked against a scanning mobility particle sizer (SMPS) and a DiSCmini by carrying out simultaneous measurements on test aerosols of ZnO or TiO₂ for particle sizes between 20 and 400 nm for which the DiSCmini has its highest accuracy. The effective density and shape of the NOAA present in the test aerosols were determined experimentally to compare number-based data obtained with the SMPS and the DiSCmini with mass-based data obtained with the NANOBADGE. The agreement between the SMPS and the NANOBADGE sampler was within ± 25 % on all test aerosols. The converted DiSCmini data matched the SMPS and sampler data for polydisperse aerosols in the specified size range as long as the DiSCmini assumptions meet the aerosol characteristics (i.e. lognormal size distribution with a given geometric standard deviation σg = 1.9). The detection limits of the NANOBADGE sampler were in the order of tens of nanograms per filter, which is low enough to reliably detect exposure levels below the recommended exposure limit (REL) of the National Institute for Occupational Safety and Health (NIOSH) and the Institut National de Recherche et de Sécurité (INRS) for ultrafine ZnO and TiO₂ even for short-term exposure situations.

It is expected a progressive increase of the industrial processes that manufacture of intermediate (iNEPs) and end products incorporating ENMs (eNEPs) to bring about improved properties. Therefore, the assessment of occupational exposure to airborne NOAA will migrate, from the simple and well-controlled exposure scenarios in research laboratories and ENMs production plants using innovative production technologies, to much more complex exposure scenarios located around processes of manufacture of eNEPs that, in many cases, will be modified conventional production processes. Here will be discussed some of the typical challenging situations in the process of risk assessment of inhalation exposure to NOAA in Multi-Source Industrial Scenarios (MSIS), from the basis of the lessons learned when confronted to those scenarios in the frame of some European and Spanish research projects.

General aerosol-measuring instruments allow real-time measurements of air particle concentrations. However, these measurements cannot distinguish free particles from target nanomaterials because they do not differentiate nanomaterials. The purpose of this study is investigation of the quantitative nature of atmospheric nanoparticles using GED (Gas Exchange Device)-ICP-MS to detect and measure nanoparticles as an element. The per particle signal intensity increased proportionally to the volume until the particle size reaches 120 nm. For all particle sizes from 20 nm to 160nm, the measured values of FMPS (Fast Mobility Particle Sizer) were consistently higher than those for ICP-MS. The system will be able to adapt to an exposure assessment of CNT (Carbon Nanotube) because carbon-base materials can be identified and quantified as long as an index element can be found.

Measures against exposure to carbon nanotubes (CNT) are necessary, especially in workplaces that handle nanomaterials, because adverse health effects are a concern. This study focuses on the dynamics of CNT released from CNT/polymer composites during the pelletizing process at a pilot factory. It is difficult to identify CNT and the base resin. By characterizing the possibility of separating CNT from the composite with a kinetic weighting coefficient, estimation can be carried out using a Computational Fluid Dynamics (CFD) simulation. The mass concentration of black carbon and the particle number concentration by diameter were measured using two different measurement apparatuses. The simulation results were then compared to the measured data. The model was verified by the correlation between the simulation and measured results. The model provided a strong correlation, indicating that the dynamics of CNT and the base resin released from the polymer composite can be simulated. It is expected that the model using the CFD simulation can be applied to the occupational health field.

The gap between release and exposure is limiting the current risk assessment of nanostructured materials. Both, release and exposure were connected to each other by transport and transformation processes and require therefore the description/specification of complex exposure scenarios. Within this study, propagation modelling based on experimentally determined airborne particle release data was used for exposure estimation and prediction in a defined model room. Therefore, 9 different exposure scenarios based on 3 release scenarios and 3 ventilation scenarios were analysed. Results for near field considerations have shown that the level of inhalation exposure is fundamentally defined by the present exposure scenario, that personal heat can cause particle availability in the breathing zone and that highest exposure levels arise immediate during material processing.

Polymer/carbon nanotube (CNT) composites exhibit distinguished properties, but more quantitative risk assessments on CNTs are necessary as research and development advances. One method to assess the exact risk is to evaluate the characteristics of nanoparticles generated from CNT composites during sanding or Taber abrasion tests. Some researchers have applied loads to CNT composites using Taber machines and analysed the particles using aerosol-measuring instruments and electron microscopes. However, employing aerosol-measuring instruments is challenging due to the small amount of generated particles. Additionally, the presence of abundant background nanoparticles in testing environments creates issues in quantitative measurements. Our research strives to develop an examination method to measure even very small amounts of nanoparticles generated by Taber abrasion. In this study, a Taber abrasion machine is miniaturised so that it fits inside a small chamber. A high-efficiency particulate air filter is attached to the chamber to eliminate background nanoparticles. Then CNT composites are abraded with the miniaturised Taber abrasion machine inside the chamber and the generated particles are analysed.

Nanostructured materials are widely used to improve the properties of consumer products such as tires, cosmetics, light weight equipment etc. Due to their complex composition these products are hardly recycled and thermal treatment is preferred. In this study we investigated the thermal stability and material balance of nanostructured metal oxides in flames and in an industrial waste incinerator. We studied the size distribution of nanostructured metal oxides (CeO₂, TiO₂, SiO₂) in a flame reactor and in a heated reaction tube. In the premixed ethylene/air flame, nano-structured CeO₂ partly evaporates forming a new particle mode. This is probably due to chemical reactions in the flame. In addition sintering of agglomerates takes place in the flame. In the electrically heated reaction tube however only sintering of the agglomerated nanomaterials is observed. Ceria has a low background in waste incinerators and is therefore a suitable tracer for investigating the fate of nanostructured materials. Low concentrations of Ceria were introduced by a two-phase nozzle into the post-combustion zone of a waste incinerator. By the incineration of coal dust in a burning chamber the Ceria nanoparticles are mainly found in the size range of the fly ash (1 – 10 µm) because of agglomeration. With gas as a fuel less agglomeration was observed and the Ceria nanoparticles were in the particle size range below 1 µm.

There have been many reports on the effect of exposure to nanomaterials such as titanium dioxide, silver, and carbon nanotube (CNT) on human health. Several experiments have examined the abrasion of CNT composites, in which CNT nanoparticles are embedded within a resin or rubber matrix, yielding varying results. Separate study of free CNTs and CNT nanoparticles in relation to health is important due to the different physicochemical characteristics of the two types of material. This study investigated the abrasion of CNT composites using a belt sander inside an enclosed chamber, with variation in the applied load and belt sander speed. At lower speeds, the population of particles with diameters of ~100 nm was observed to increase (cf. mode values of ~10 nm), and we found a relationship between the amount of the raising dust and the abrasion conditions. From these results, we propose a robust and widely applicable method to create particles of nanomaterial-containing composite materials of various types in order to conduct accelerated exposure assessment studies.

The release of free carbon nanotubes (CNTs) and CNTs partly embedded in matrix debris into the air may occur during mechanical and abrasion processes involving CNT composites. Since the harmful effects of CNT-matrix mixtures have not yet been fully evaluated, it is considered that any exposure to CNTs, including CNT-matrix mixtures, should be measured and controlled. Thermal carbon analysis, such as Method 5040 of the National Institute for Occupational Safety and Health, is one of the most reliable quantitative methods for measuring CNTs in the air. However, when CNTs are released together with polymer matrices, this technique may be inapplicable. In this study, we evaluated the potential for using thermal carbon analysis to determine CNTs in the presence of polymer matrices. Our results showed that thermal carbon analysis was potentially capable of determining CNTs in distinction from polyamide 12, polybutylene terephthalate, polypropylene, and polyoxymethylene. However, it was difficult to determine CNTs in the presence of polyethylene terephthalate, polycarbonate, polyetheretherketone, or polyamide 6.

We investigated airborne particles released as a result of crushing carbon nanotube (CNT) composites using a laboratory scale crusher with rotor blades. For each crushing test, five pellets (approximately 0.1 g) of a polymer (polystyrene, polyamide, or polycarbonate) containing multiwall CNTs (Nanocyl NC7000 or CNano Flotube9000) or no CNTs were placed in the container of the crusher. The airborne particles released by the crushing of the samples were measured. The real-time aerosol measurements showed increases in the concentration of nanometer- and micrometer-sized particles, regardless of the sample type, even when CNT-free polymers were crushed. The masses of the airborne particles collected on filters were below the detection limit, which indicated that the mass ratios of the airborne particles to the crushed pellets were lower than 0.02%. In the electron microscopic analysis, particles with protruding CNTs were observed. However, free-standing CNTs were not found, except for a poorly dispersed CNT-polystyrene composite. This study demonstrated that the crushing test using a laboratory scale crusher is capable of evaluating the potential release of CNTs as a result of crushing CNT composites. The advantage of this method is that only a small amount of sample (several pieces of pellets) is required.

Throughout the EU funded FP7 project GUIDENano, we are trying to control and monitor the evolution of nano-enable products during their lifecycle. Small alterations of the nanoparticle (NP) state may have critical consequences on the NP behaviour and performance. For this reason it is important to highlight the importance of an extensive and proper characterization to define the NP physico-chemical characteristics under several environmental conditions. Furthermore, this characterization is necessary to ensure that obtained results are reproducible and allow understanding the behaviour of the NP on biological systems. In this paper different strategies reported in the literature regarding the safety-by-design concept are summarized. Several strategies from the synthetic point of view that help us to modulate the main factors which determine the safety of nanomaterials are proposed.

Since there is a lack of sufficient toxicological information about engineered nanomaterials, and since within the semiconductor research and manufacturing use is already made of these materials, an alternative for the classical quantitative risk assessment was sought. Within the research facilities of imec use is made of a banding technique to determine the risks associated with the nanomaterial research. The method and the measures that are taken are discussed in the paper. The method has been benchmarked with other available techniques.

The project PLATFORM (H2020, GA 646307) aims to develop three new pilot lines (PPLs) for the manufacture of carbon nanotube-based nano-enabled products (buckypapers, treated prepregs, doped veils), for the European aeronautics and automotive industries (a Technology Readiness Level 6 - TRL6 - is expected at the end of the project). The Machinery Directive 2006/42/EC (MD) - transposed into the respective national legislations - is the European regulatory framework for the design and construction of new machinery, as the future PPLs. PPLs are not required to comply with the provisions of the MD until they are put into service - expected in 2020, after project completion - but then, the MD will be fully applicable. In this regulatory context, the project PLATFORM is aligning the design of the PPLs according to the MD requirements, in order to facilitate the CE marking in 2020 (TRL9) and avoid potential economic costs associated with future re-adaptations or modifications needed to ensure compliance with the MD. This paper discusses the methodological approach followed by the project PLATFORM to integrate all the nanosafety aspects in the design of the PPLs, in order to achieve safe designs in conformity with the relevant Essential Health and Safety Requirements (EHSRs) of the MD. Since machinery must be designed and constructed taking into account the results of the risk assessment (RA), this paper describes the systematic and iterative approach for RA and risk reduction followed to eliminate hazards as far practicable and to adequately reduce risks by the implementation of protective measures. This process has been guided by the harmonized standards EN ISO 12100 and EN ISO 14123, taking the relevant phases of life cycle, expected uses and operation modes of the PPLs into account. A specific tool to guide the safe design of the PPLs and facilitate the RA process has also been produced by the project (PLATFORM – SbD toolkit).

The Safe-by-Design (SbD) concept is already in use in different industrial sectors as an integral part of the innovation process management. However, the adopted approach is often limited to design solutions aiming at hazard reduction. Safety is not always considered during the innovation process, mainly due to the lack of knowledge (e.g. in small and medium companies, SMEs) and the lack of dialogue between actors along the innovation chain. The net result is that safety is considered only at the end of the innovation process at the market authorization phase, with potential loss of time and money. This is especially valid for manufactured nanomaterials (MNM) for which the regulatory context is not completely developed, and the safety knowledge is not readily available. In order to contribute to a sustainable innovation process in the nanotechnology field by maximising both benefits and safety, the NANoREG project developed a Safe Innovation approach, based on two elements: the Safe-by-Design approach which aims at including risk assessment into all innovation stages; and the Regulatory Preparedness, focused on the dialogue with stakeholders along the innovation chain. In this work we present some examples about the implementation in our Laboratory of this approach for different MNM applications, covering different steps of the innovation chain. The case studies include: the feasibility study of a medical device including substances, for topical application; the testing of two potential nanotech solutions for the consolidation of cultural heritage artifacts; the testing of coatings already on the market for other uses, which was tested as food contact materials (FCM) to evaluate the conformity to food applications. These three examples represent a good opportunity to show the importance of NANoREG SbD and Safe Innovation Approach in general, for developing new nanotechnology-based products, also highlighting the crucial role of EU ProSafe project in promoting this concept to industries and interested stakeholders.

In recent decades, the control banding (CB) approach has been recognised as a hazard assessment methodology because of its increased importance in the occupational safety, health and hygiene (OSHH) industry. According to the American Industrial Hygiene Association, this approach originates from the pharmaceutical industry in the United Kingdom. The aim of the CB approach is to protect more than 90% (or approximately 2.7 billion) of the world's workers who do not have access to OSHH professionals and traditional quantitative risk assessment methods. In other words, CB is a qualitative or semi-quantitative tool designed to prevent occupational accidents by controlling worker exposures to potentially hazardous chemicals in the absence of comprehensive toxicological and exposure data. These criteria correspond very precisely to the development and production of engineered nanomaterials (ENMs). Considering the significant lack of scientific knowledge about work-related health risks because of ENMs, CB is, in general, appropriate for these issues. Currently, CB can be adapted to the specificities of ENMs; hundreds of nanotechnology products containing ENMs are already on the market. In this context, this qualitative or semi-quantitative approach appears to be relevant for characterising and quantifying the degree of physico-chemical and biological reactivities of ENMs, leading towards better control of human health effects and the safe handling of ENMs in workplaces. The need to greater understand the CB approach is important to further manage the risks related to handling hazardous substances, such as ENMs, without established occupational exposure limits. In recent years, this topic has garnered much interest, including discussions in many technical papers. Several CB models have been developed, and many countries have created their own nano-specific CB instruments. The aims of this research were to perform a literature review about CBs, to classify the main approaches that were developed worldwide, and then to suggest an original methodology based on the characterisation of the hazard. For this research, our team conducted a systematic literature review over the past 20 years. This approach is important in understanding the conceptual basis for CB and the model's overall effectiveness. These considerations will lead to the proposal of an original hazard assessment method based on physico-chemical and biological characteristics. Such a method should help the entire industry better understand the ability of the CB approach to limit workers' exposure, while identifying the strengths and weaknesses of the approach. Developing this practice method will help to provide relevant recommendations to workers who handle hazardous chemicals such as ENMs and to the general population.

The rapid expansion of nanotechnology is outpacing health and safety recommendations for engineered nanomaterials. Thus, there is a lack of information about the effects that nanomaterials can induce in the human health. Nevertheless, workers in nanotechnology-related industries are potentially at risk of being exposed to nanomaterials. Therefore, there is a need of characterize the behaviour of personal protective equipment against penetration nanoparticles, in order to provide an adequate protection to the workers. In this study, the efficiency of several protective dermal equipment against water-based NaCl aerosol was evaluated. For this purpose, different protective clothing and gloves were selected to carry out the assays, simulating typical use conditions of protective equipment under occupational settings. Results obtained exposed that the level of protection offered by the distinct types of personal protective coveralls depended not only on the fabric, but also on their fitting to the body of the subject. On the other hand, the efficiency of the protective gloves was set in the range from 95% to 99%, depending on the thickness and the type of material.

Nanoparticles are widely used in industrial applications as additives to modify materials properties such as resistance, surface, rheology or UV-radiation. As a consequence, the quantification and characterization of nanoparticles have become almost compulsory, including the understanding of the risks associated to their use. Since a few years ago, several studies of dust explosion properties involving nano-sized powder have been published. During the production and industrial use of nanoparticles, simultaneous presence of gas / vapor / solvents and dispersed nanoparticles mixtures might be obtained, increasing the risk of a hybrid mixture explosion. The aim of this work is to study the severity of the explosion of carbon black nanoparticles/methane mixtures and understand the influence of adding nanopowders on the behavior of the gas explosions. These results are also useful to understand the influence of soot on the efficiency of the gas combustion. Two grades of carbon black nanoparticles (ranging from 20 to 300 nm average diameter) have been mixed with methane. Tests have been performed on these mixtures in a standard 20 L explosion sphere. Regarding the scale precision, the lowest concentration of carbon black nanoparticles was set at 0.5 g.m-3. Tests were also performed at 2.5 g.m-3, which is still far below 60 g.m-3, the minimum explosive concentration of such powders previously determined in our laboratory. The influence of carbon black particles on the severity of the explosions has been compared to that of pure gas. It appears that the use of carbon black nanoparticles increases the explosion overpressure for lean methane mixtures at low initial turbulences by c. 10%. Similar results were obtained for high initial turbulent systems. Therefore, it seems that carbon black nanoparticles have an impact on the severity of the explosion even for quiescent systems, as opposed to systems involving micro-sized powders that require dispersion at high turbulence levels. Concerning the increment in the maximum rate of pressure rise, the addition of carbon black nanoparticles increased it by a factor of 1.15 in the case of lean fuel mixture. However, this behavior is only observed at high initial turbulence levels. The increment on the maximum rate of pressure rise is higher for powders with lower elementary particle diameter, which is notably due to the fragmentation phenomena that promotes the heat exchange.

The potential environmental risk arising from the incineration of waste containing nanomaterials is a new field which deserves further attention. Some recent studies have begun to focus on this topic but the data are incomplete. In addition, there is a need to consider real life waste.

The present study gives some insight into the fate and behavior of a commercial coating containing a commercial additive (7% w/w) based on nano-CeO2 (aggregates of 10 to 40 nm, with elemental particles of 2-3 nm). The tests have been conducted with a system developed in the frame of the NanoFlueGas project. The test protocol was designed to respect the regulatory criteria of a good combustion in incineration plants (temperature around 850°C, highly ventilated combustion, at least 2 s residence time for the combustion gas in a post-combustion chamber at 850°C, and high oxygen/fuel contact).

Time tracking by electric low pressure impaction (ELPI) shows that the incineration produces aerosol with number concentration dominated by sub-100 nm particles. Cerium is observed by TEM and EDS analysis but as a minor compound of a sub-group of particles. No nanoCeO2 particles have been observed in the aerosol.

ICP-MS analysis indicates that the residual material consists mainly of CeO2 (60% of the mass). Observation by TEM establishes that this material is in the form of aggregates with individual particle of 40-200 nm and suggests that sintering occurred during incineration.

As a conclusion, the lab scale incineration study led mainly to the release of nano-CeO2 in the residual material, as the major component. Its size distribution is different than the one of the nano-CeO2 observed in the initial sample before incineration. Additional research is needed to improve the understanding of nanoCeO2 behavior, and to integrate experiments at lab and real scale.

Considering the wide use and production of NMs since last two decades, these trendy nanomaterials (NMs) are expected to end up in thermal disposal and waste incineration plants (WIP). It seems relevant to assess the risks related to the thermal disposal and incineration of waste containing NMs (WCNMs). The objective of this work is to present a first approach to develop a preliminary methodology for risk management in order (1) to give insights on nanosafety of exposed operators and on potential environmental risks related to the incineration and thermal disposal of WCNMs, and (2) to eventually support decision-makers and incineration plant managers. Therefore, the main challenge is to find (a) key parameter(s) which would govern the decision related to risk management of NMs thermal disposal. On the one hand, we focused on the relevant literature studies about experimental works on incineration of NMs. On the other hand, we conducted an introductory discussion with a group of experts. The review of this literature highlights that the nano-object's nanostructure destruction appears as a relevant indicator of the risks related to the NMs incineration. As a consequence, we defined a "temperature of nanostructure destruction" (TND) which would be the temperature from which the nanostructure will be destroyed. This parameter has been assumed to be a consistent indicator to develop a preliminary methodology. If the combustion chamber temperature is higher than the TND of the NM (or if they are close to each other), then the nanostructure will be destroyed and no risks related to NMs remain. If the TND of the NMs is higher than the combustion chamber temperature, then the nanostructure will not be destroyed and risks related to NMs have to be considered. As a result, five groups of NMs have been identified. WCNMs including carbonic NMs appear to be in good position to be destroyed safely in WIP. On the other hand, based on this criterion, there would be no available thermal disposal plants to safely manage WCNMs including CeO2 and ZrO2. Finally, a decision tree has been designed. TND is used as criteria to assess if a waste can be managed safely or not by a specific thermal disposal and which safety measures have to be taken.

Engineered Nanomaterials (ENM) provide technical and specific benefits due to their physical-chemical properties at the nanometer scale. For instance, many ENM are used to improve products in the building industry. Nanoscaled titanium dioxide (TiO₂) is one of the most used ENM in this industry. Incorporated in different matrix, cement, glass, paints... TiO₂ nanoparticles (NPs) provide the final product with anti-UV, air purification and self-cleaning properties, thanks to their photocatalytic activity. However, ageing processes of such products, as photocatalytic paints, during a mechanical stress have been shown to release TiO₂ NPs from this matrix associated with sanding dust. Thus, workers who sand painted walls could be exposed to TiO₂ NPs through inhalation. As inhalation may lead to a translocation of particulate matter to the brain via olfactory or trigeminal nerves, there is an urgent need for evaluating a potential neurotoxicity. In order to provide new knowledge on this topic, we developed a dedicated experimental set-up using a rodent model exposed via inhalation. The aerosol released from a mechanical stress of photocatalytic paints containing TiO₂ NPs was characterized and coupled to an exposition chamber containing group of mice free to move and chronically exposed (2 hours per day for 5 days a week during 8 weeks).

Graphene oxide, a widely studied nano materials, exhibits numerous beneficial effects in medical devices. The graphene sample Graphene oxide (GO):Single-layer graphene oxide, purity 99%, thickness 0.7-1.2 nm (AFM); ~300-800nm X&Y dimensions is the standard size <450 nm & 1-20 µm lateral dimensions from Cheap Tubes Inc., Bratleboro, USA was selected for this study. Characterization of GO and stability were previously studied. All the assays were carried out at a concentration of 1 mg/mL (stock suspension by ultrasonication)(stable 10 days). In this study the first parameter evaluated was in animal toxicity in acute and chronic responses. The second one was to observe the morphology and histological changes on major organs, like signs of inflammatory areas. A total of 25 rats (Fischer 344) were divide in 5 groups (n = 5 animals): negative control group (NCT); Positive cancer control group (PCCT); GO group-1 (GO 1); GO group-2 (GO 2) and GO group-3 (GO 3), with different concentrations of graphene oxide. All the groups were treated by via intra peritoneal (i.p) administration. Biochemical and histopathology results of acute toxicity showed no alterations. In the chronic toxicity was found deposit sections and morphology alterations in different tissues (inflammations). Genotoxicity was dose dependent of GO. This study gave us the limit concentrations of GO free for any biological study.

Nanostructured lipid carriers (NLCs) are active carrier systems which modulate the sustained release of actives and protect unstable compounds against degradation. NLCs can also protect skin from sun light, due to its particulates nature, which gives them intrinsic scattering properties. In this work, we present the preparation of NLCs using natural lipids and its cytotoxicity profile. It was used a vegetal butter with melting point (m.p.) ~32-40°C, an animal wax (m.p. 35-40°C) and a vegetal oil (boiling point ~120-150°C). NLCs were prepared by hot high pressure homogenization method and particles were characterized by average size (Z_ave), polydispersity index (PDI) and zeta potential (PZ) (Fig.1). The thermal behavior of the NLCs was studied using Differential Scanning Calorimetry (DSC). All the formulations were followed up for 60 days in order to evaluate their stability. NLCs exhibited a Z_ave around 150-200 nm, PDI less than 0.2 and PZ varying from −25 to −40 mV. The m.p. for the lyophilized NLCs was about 40-56°C. Cytotoxicity of the formulations were evaluated for human keratinocytes (HaCaT) and melanocytes (Melan-A) in the exponential growth phase. Cell viability was used as indicator of cytotoxicity and determined after 4 days of culture by MTT assay. It was found that the NLC formulations were not toxic against HaCaT and Melan-A cells. Results showed that the NLCs produced are potential carriers for nanocosmetics and sunscreen products.

It is known the presence of carbon dots (CDs) in carbohydrate based foods. CDs extracted from coffee grounds and instant coffee was also published. CDs from soluble coffee revealed an average size of 4.4 nm. CDs were well-dispersed in water, fluorescent and we have characterized by XPS, XRD analysis, fluorescence and by FTIR spectra. The MIC value by serial micro-dilution assays for CDs on S. aureus ATCC 25923 was 250 μg/mL and E. coli ATCC 25922 >1000 ug/mL. For silver nanoparticles biogenically synthesized was 6.7 μg/mL. Following the checkerboard assay with combining ½ MIC values of the MICs of 125 μg/mL of carbon dots and 3.4 μg/mL of silver nanoparticles, following the fractionated inhibitory concentration (FIC) index methodology, on S. aureus gave a fractionated inhibitory concentration (FIC) value of 1.0, meaning additive interaction. In general, the unfunctionalized CDs showed to be inefficient as antibacterial compounds, however the CDs extracted from Coffee powder and together silver nanoparticles appeared interesting as antibacterial association.

A complex of express methods for cyto-, geno-, and embryotoxicity assessment of nanoparticles (NPs), based on the simultaneous use of three models: the cultures of pre- and post-implantation embryos of mice (egg cleavage, blastocyst formation, 1−5 day of development) and rats (head fold−neurulation stages, 30 somite pairs, 9.5−11.5 day of development), as well as human peripheral blood lymphocytes, is developed. Pathogenic (dysmorphogenic) effects of SiO₂ NPs in concentrations of 100 and 200 µg/mL on early embryo development processes were established. The cytogenetic methods used for cyto-, geno-, and mutagenicity assessment (micronuclear test under cytokinesis-block conditions, chromosomal aberrations test, and DNA comet assay) revealed no effects of SiO₂ NPs in concentrations 200, 100, and 20 µg/mL.

Graphistrength© C100 provides superior electrical and mechanical properties for various applications and is one of the industrial MWCNT referenced in the OECD sponsorship program for the safety testing of nanomaterials. Graphistrength© C100 is formed of MWCNT (ca. 12 walls, outer mean diameter ca. 12 nm, length ca. 1 µm) agglomerated in particles with a granulometry centered on 400 µm. A general feature of MWCNT after inhalation or intratracheal exposures is the induction of an inflammatory reaction in the lungs sometimes associated with local genotoxic effects. Most of the in vitro and in vivo genotoxicity data available on Graphistrength© C100 are negative. However, a weak DNA damage activity in the in vitro and in vivo FPG-modified Comet assays and a weak clastogenic effect in the in vitro micronucleus test were reported. After investigating different parameters for the aerosol generation, male and female Wistar rats were exposed by nose-only inhalation (6h/day, 5d/week) to target concentrations of 0.05, 0.25 and 5.0 mg/m³ air of a respirable aerosol (MMAD < 3 µm) and sacrificed immediately after 4 and 13 weeks of exposure and 13 and 52 weeks of recovery after the 13-week exposure. Clinical, biological and histological evaluations were performed according to the OECD TG 413. Broncho-alveolar lavage fluid (BALF) was collected and analysed for cytokines and inflammatory parameters. Immediately after 13 weeks of exposure, chromosomal aberrations in the bone marrow cells of males and females were evaluated by the micronucleus test (OECD TG 474) and DNA damage in the lung, kidney and liver cells of males were assessed by both the standard and the human 8-oxoguanine DNA N-glycosylase 1 (hOGG1)-modified comet assay (OECD TG 489). Concentration-related deposition of black particles (MWCNT) was observed in lungs. At all sacrifice periods, an inflammatory lung reaction was observed in rats exposed to 5.0 mg/m³ associated with changes in the differential white blood cells counts. The lung inflammation was characterized by changes in the cytological, biochemical and cytokine parameters of the BALF, an increase of the lung weight, an interstitial inflammation mainly around the alveolar ducts at the bronchiole-alveolar junction and a cell hypertrophy/hyperplasia in the terminal and respiratory bronchioles. The slight changes in BALF parameters observed at 0.25 mg/m³ recovered after the 13-week treatment-free period and were not associated with any of the histological changes observed in lungs at 5.0 mg/m³. Signs of lung clearance of the MWCNT were observed at 0.05 and 0.25 mg/m³. After a one year treatment-free period, the inflammatory lung reaction was slight and of similar intensity that at the earlier sacrifice periods. Additional findings were minimal/slight bronchiolar/alveolar cell hypertrophy/hyperplasia and focally extensive alveolar septal fibrosis. No other pathological change was observed, nor was there any brain translocation via the olfactory bulb. The microscopic observations of the pleura were unremarkable. Neither increase in the number of micronucleated polychromatic erythrocytes nor increase in percent DNA damage were observed at any concentration. In conclusion, a lung inflammation characteristic of an overload with insoluble particles was observed after a 13-week inhalation exposure to 5.0 mg/m³ of Graphistrength© C100. A No-Observed Adverse Effect Concentration (NOAEC) of 0.25 mg/m³ was established for the repeated-dose toxicity and Graphistrength© C100 appears of low concern in term of local and systemic genotoxicity.

Silver nanoparticles (AgNPs) are well known potent antimicrobial agents. Similarly, the free radical nitric oxide (NO) has important antibacterial activity, and due to its instability, the combination of NO and nanomaterials has been applied in several biomedical applications. The aim of this work was to synthesize, characterize and evaluate the antibacterial activity of a new NO-releasing AgNPs. Herein, AgNPs were synthesized by the reduction of silver ions (Ag⁺) by catechin, a natural polyphenol and potent antioxidant agent, derived from green tea extract. Catechin acts as a reducing agent and as a capping molecule on the surface of AgNPs, minimizing particle agglomeration. The as-synthesized nanoparticles were characterized by different techniques. The results showed the formation of AgNPs with average hydrodynamic size of 44 nm, polydispersity index of 0.21, and zeta potential of −35.9 mV. X-ray diffraction and Fourier transform infrared spectroscopy revealed the presence of the AgNP core and cathecin as capping agent. The low molecular weight mercaptosuccinic acid (MSA), which contain free thiol group, was added on the surface of catechin-AgNPs, leading to the formation of MSA-catechin-AgNPs (the NO precursor nanoparticle). Free thiol groups of MSA-catechin-AgNPs were nitrosated leading to the formation of S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), the NO donor. The amount of 342 ± 16 µmol of NO was released per gram of S-nitroso-MSA-catechin-AgNPs. The antibacterial activities of catechin-AgNPs, MSA-catechin-AgNPs, and S-nitroso-MSA-catechin-AgNPs were evaluated towards different resistant bacterial strains. The results demonstrated an enhanced antibacterial activity of the NO-releasing AgNP. For instance, the minimal inhibitory concentration values for Pseudomonas aeruginosa (ATCC 27853) incubated with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-S-nitroso-MSA were found to be 62, 125 and 3 µg/mL, respectively. While in the case of Klebsiella pneumoniae (ATCC 700603) the minimum bactericidal concentration values for treatments with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-S-nitroso-MSA were found to be 1000, 500, and 125 µg/mL, respectively. The antibacterial actions of the NO-releasing nanoparticle were superior in comparison with the antibacterial effects of AgNPs, in most of the tested antibiotic resistant bacteria strains. These results highlight the promising uses of NO-releasing AgNPs against resistant bacteria in several biomedical applications.

Nitric oxide (NO) is an endogenous free radical, which plays key roles in several biological processes including vasodilation, neurotransmission, inhibition of platelet adhesion, cytotoxicity against pathogens, wound healing, and defense against cancer. Due to the relative instability of NO in vivo (half-life of ca. 0.5 seconds), there is an increasing interest in the development of low molecular weight NO donors, such as S-nitrosothiols (RSNOs), which are able to prolong and preserve the biological activities of NO in vivo. In order to enhance the sustained NO release in several biomedical applications, RSNOs have been successfully allied to nanomaterials. In this context, this work describes the synthesis and characterization of the NO donor S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), which belongs to the class of RSNOs, and its incorporation in polymeric biodegradable nanoparticles composed by alginate/chitosan. First, chitosan nanoparticles were obtained by gelation process with sodium tripolyphosphate (TPP), followed by the addition of the alginate layer, to enhance the nanoparticle protection. The obtained nanoparticles presented a hydrodynamic diameter of 343 ± 38 nm, polydispersity index (PDI) of 0.36 ± 0.1, and zeta potential of − 30.3 ± 0.4 mV, indicating their thermal stability in aqueous suspension. The negative zeta potential value was assigned to the presence of alginate chains on the surface of chitosan/TPP nanoparticles. The encapsulation efficiency of the NO donor into the polymeric nanoparticles was found to be 98 ± 0.2%. The high encapsulation efficiency value was attributed to the positive interactions between the NO donor and the polymeric content of the nanoparticles. Kinetics of NO release from the nanoparticles revealed a spontaneous and sustained release of therapeutic amounts of NO, for several hours under physiological temperature. The incubation of NO-releasing alginate/chitosan nanoparticles with human hepatocellular carcinoma (HepG2) cell line revealed a concentration-dependent toxicity. These results point to the promising uses of NO-releasing alginate/chitosan nanoparticles for anti-cancer chemotherapy.

Oxidative stress is a widely accepted paradigm associated with different adverse outcomes of particulate matter, including nanomaterials. It has frequently been identified in in vitro and in vivo studies and different assays have been developed for this purpose. Here we describe a newly developed multi-dose protocol of the FRAS assay (Ferric Reduction Ability of Serum). The purpose of this SOP is the measurement of the surface reactivity of nanomaterials under physiological conditions. Antioxidative components as present in human blood serum (HBS) serve as reporter molecules. The assay separates the oxidative damage from the read-out of the reporter molecules. The results show significantly enhanced repeatability with better sensitivity towards low reactivity, enabling application of FRAS both to a rough grouping by reactive vs. passive nanomaterials and further to substantiation of read-across by enhanced resolution of the similarity between different nanoforms of the same substance.

Phosphate esters are employed in some agrochemical formulations and have long life time in the Environment. They are neurotoxic to mammals and it is very difficult to hydrolyze them. It is easy to find papers in the literature dealing with transition metal complexes used in the hydrolysis processes of organophosphorous compounds. However, there are few reports related with degradation of phosphate esters with inorganic nanoparticles. In this work bis-4-nitrophenyl phosphate (BNPP) was used as an agrochemical agent model. The BNPP interaction with zero-valent iron nanoparticles (ZVI NPs), in aqueous media, was searched. The concentration of BNPP was 1000 times higher than the ZVI NPs concentration. The average size of the used iron nanoparticles was 10.2 ± 3.2 nm. The BNPP degradation process was monitored by means of UV-visible method. Initially, the BNPP hydrolysis happens through the P-O bonds breaking-off under the action of the ZVI NPs. Subsequently, the nitro groups were reduced to amine groups. The overall process takes place in 10 minutes. The reaction products were identified employing standard substances in adequate concentrations. The iron by-products were isolated and characterized by X-RD. These iron derivatives were identified as magnetite (Fe₃O₄) and/or maghemite (γ-Fe₂O₃) and lepidocrocite (γ-FeOOH). A suggested BNPP degradation mechanism will be discussed.

Nanotechnology has been more present in different fields related to health. The need to find a durable material, of easy use, and which does not interfere significantly in the growth and differentiation of stem cells for the construction of a scaffold for use in urologic surgery, with the purpose of reducing infections, regeneration times and even graft rejection during reconstitution in patients with urethral stricture was conducted a broad survey of information about this and came to the consensus of this project: using graphene oxide, a widely studied nanomaterials which has been presenting numerous beneficial results when in contact with the adipose-derived stem cells. Advanced techniques for the growth, differentiation and proliferation of adipose-derived stem cells were used, as well as the characterization of graphene oxide sheets. For this study, it was prepared the graphene oxide/6 ARM-Poly (ethylene glycol) amine films with poly (ε-caprolactone). The graphene suspension in organic solvent was prepared by using an ultrasonicator bath and subsequently, the film was formed by solvent evaporation. Total characterization of graphene oxide/6 ARM-PEG-amine/ poly (ε-caprolactone) film was carried out. It was tested growth and adhesion of adipose-derived stem cells on the film, as well as, were verified the histopathological effects of this scaffold when implanted in the urinary bladder to repair the lesion. Our results demonstrated that this scaffold with adipose-derived stem cells enhanced the repair in rat urinary bladder defect model, resulting in a regular bladder. Improved organized muscle bundles and urothelial layer were observed in animals treated with this scaffold with adipose-derived stem cells compared with those treated only suture thread or scaffold. Thus, our biomaterial could be suitable for tissue engineered urinary tract reconstruction.

The particle count, surface and mass in an occupied space can be modeled when the HVAC system airflows are known, along with the particle-size distribution for outdoor air, internal generation rates as a function of particle size, and the efficiency as a function of particle size for filters present. Outdoor air particle-size distribution is rarely available, but measures of particle mass concentration, PM_2.5 and PM₁₀, are often available for building locations. Outdoor air aerosol size distributions are well modeled by sums of two or three log-normal distributions, with essentially all mass in two larger modes. Studies have also shown that some mode parameters are, in general, related by simple functions. This paper shows how these relationships can be combined with known characteristics of PM_2.5 and PM₁₀ samplers to create reasonable inclusive models of outdoor air aerosol-size distributions. This information plus knowledge of indoor particle generation allows calculation of aerosol mass in occupied spaces. Estimation of parameters of aerosol modes with sizes below100 nm and measurement of filter efficiencies in that range are described.