Nano risk evaluation in laboratory environment by a customized layer of protection analysis approach

Nanotechnologies are widely used in various industrial settings and by the year 2020, it is expected that nearly 20 % of all products manufactured in the world will take a certain amount of nanotechnology. However, there is a substantial imbalance of knowledge between application of nanotechnology and its impact on health and environment, also considering that nanoparticle synthesis by chemical methods assumed a key role for economic, industrial and scale-up issues. The information currently available on nanomaterial risk assessment within the workplace are limited: systematic methods for assessing exposure are not known yet and the number of workers exposed is hardly estimated. This knowledge gap imposes to the scientific community the need to join efforts to provide a shared opinion on safety, health and welfare of workers who use, manipulate, or produce nanomaterials, adopting as well preventive and protective measures proportionated to the risk according to the precautionary principle. We develop a novel framework for Nano Risk Assessment within the laboratory context, by combining LOPA and HazId techniques, assigning credit factors to specific operative procedures and safety training, suitable to mitigate risk exposure and avoid over-conservative evaluations. Conclusions are drawn on applicative results and possible direction for further implementation of the approach, in view of sustainable, healthy and safe production at research and industrial level

Generalisation of the solution of the inverse Richards' problem

In inverse problems defined by models that include partial differential equations, a part of the boundary conditions are unknown and are to be estimated from experimental measurements. We have shown in a previous contribution that the solution of the inverse Richards' problem can allow estimating percolation rates at the bottom of landfills through the use of measurements at the surface only. This can be a useful complement of the information furnished by the vadose measurement system, pointing to the possible presence of biases of in-situ equipment, and making it possible to use inexpensive mobile equipment to carry out surface measurements. In this article, we consider a generalisation which makes it possible to consider the presence of unknown nonlinear parameters, such as the effective hydraulic conductivity and the root uptake coefficients. This is accomplished using the method of separation of variables in the resulting estimation problem. Thanks to the linearity of the model, all these conditions can be expressed as linear functions of the unknown lower boundary condition. Otherwise, the relevant non-linear parameters are to be estimated from the data as well. Obviously, the correlation between the linear parameters contained in the unknown lower boundary conditions and the non-linear parameters can reduce the reliability of the monitoring procedure and hence the necessity of limiting the number of the latter

Ageing and creeping management in major accident plants according to seveso III directive

The focus of this paper is the management of critical equipment ageing within the context of lower and upper tier Seveso process plants, with a peculiar insight into the effectiveness of safety management systems in setting-up reliable procedure for critical element identification. Recent research studies in fact evidenced that in Europe nearly 50% of major 'loss of containment' events, arising from technical plant failures, were primarily due to ageing plant mechanisms such as erosion, corrosion and fatigue. The critical ageing elements should be included in maintenance, inspection and periodic monitoring programs in relation to their reliability, as assumed in the risk assessment and their lifetime or frequency ranges, based on their operational experience. This paper will accurately discuss how the issue of ageing is currently handled in the process industry. The methodology builds on the critical results of actual findings from the inspections on the safety management systems of major accident plants, which were performed by a working group. The primary objective is to stimulate the introduction of effective ageing management changes into the safety management of companies, by taking advantages of findings of the previous assessment and establishing proper and effective audits

Cobalt-based nanoparticles synthesis in organic solvents with environmentally sound processes

A process for the synthesis of cobalt-based nanoparticles is proposed, where standard reducing agent like hydrazine, alkali metal borohydrides, hypophosphites or other toxic reducing agents have not been employed. The solvothermal reaction is carried out in organic solvents and the dimension of the nanoparticles thus obtained have been analyzed by dynamic light scattering. Cobalt nitrate proved to be an efficient precursor, in agreement with previous literature works where its suitability for analogous processes has been tested and compared with the efficiency typical of other precursors routinely used. The soundness of this method, in terms of process safety, has been checked by analyzing the formation of toxic by-products that could be formed by side-reactions between the precursor and the solvent. This work may add some more details to a discussion pertaining to the accidental formation of N-nitroso derivatives of aliphatic compounds in the presence of alkanolamines and oxides of nitrogen

New trends in the synthesis of nanoparticles by green methods

In this brief survey, we deal with green processes concerning the synthesis of zerovalent nanoparticles, enlighting some aspects motivating their choice with respect to traditional techniques generally relying upon toxic or noxious reactants and stabilizing agents. After a short discussion about health and environmental safety related to the use of standard reductants, we run through several green methods for metal nanoparticle synthesis and we split them into two basic classes, according to the electropositivity of the elements which the nanoparticles are made of. This classification has been proposed in order to account for strengths and weaknesses of processes based on active substances of biological origin that, though being effective in the production of noble metal nanoparticles, proved to be much less suitable when tested in the synthesis of nanoparticles made of more electropositive elements. The goal of this work is essentially oriented to stimulating new research trends for the eco-friendly production of nanosized non-noble elements deserving more attention by current nanobiotechnology

An oil pipeline catastrophic failure: Accident scenario modelling and emergency response development

In spite of advanced technologies, inherent safety and safety management system, pipeline loss of containments and large-scale releases of hazardous substances are still common accidents leading to severe consequences for human health, environment and assets, both in Europe and in developing Countries. This paper presents a detailed analysis of the catastrophic failure of a pipeline connecting the port oil terminal with a downstream oil plant, in the North part of Italy, causing a major oil spill into a river and subsequently into the Genoa harbor (Italy). Firstly, the impact of atmospheric dispersion is evaluated then, assuming oil containment failure, the hydrodynamic dispersion of the spill into the sea is studied. By means of numerical methods, we performed a consequence-based assessment incorporating the effects, the hazardous distance and the reaction time scale, related to oil spill. Results are focused on the atmospheric dispersion of the "key" oil volatile fractions and the propagation in the sea of the medium-heavy fractions, both performed by Lagrangian simulations

Understanding the Vulnerability of Complex Systems. An Integrated Approach

The increasing complexity of current system realities (e.g., pandemics, healthcare, energy transition, process industry 4.0 etc.) would require the evaluation of the actual way systems are modified, often referred with “work as done”, rather than “work as imagined”. The safety of a complex system is one of the emergent properties depending upon the interactions between the system's components and subsystems. This paper is focused on the analysis of the nature of the interactions within a complex system when it is subjected to cumulative stresses, crises and accidents. The objective is to identify, test and validate integrated emergency management procedures in the event of accidents, crises or major incidents occurring during the loading and unloading of goods and hazardous substances. To test the applicability of the framework, we developed a prototypal application identifying as a target complex system an Italian port area. An interactive simulation model was ad-hoc designed and developed, which makes it possible to reproduce the evolution of the crisis and its impact on structures, systems, people and goods by considering both the physical aspects and the domino effect in a multiple/sequential accidental scenario simulation. Additionally, it is possible testing the effectiveness of new technological and infrastructural solutions to reduce vulnerability, mitigate damage and prevent possible escalation of the event. Relevant accident scenarios were firstly thoroughly selected and subsequently integrated into a digital twin of the port. The interactivity allows a dynamic simulation of the possible actions of the different elements and active subsystems considered as a complex system, exploring their interactions in the face of crises and disasters, including the determining role of human factor

Inorganic nanoparticles synthesis by an aerosol-assisted wet chemical method

Many successful methods for nanoparticle synthesis are based on a comminution of the phases containing the precursors prior to the chemical reactions. The beneficial effects of such techniques are well-known in terms of small dimensions and narrow distributions of diameters of the nanoparticles thereby produced. According to specific methods, micelles or droplets behave as segregated micro-reactors where reactants are made to combine with minimization of further aggregation, to improve the quality of the final product. In the present paper, an aqueous solution of a reagent is nebulized on the surface of a stirred liquid containing the second reagent, with formation of a nanosized solid phase with diameter and height ranges of 50-100 nm and 6-8 nm, respectively. We are not aware of other wet-chemical methods based on such a technique, which proves to be simpler and more inexpensive than the typical one of traditional spray processes followed by high-temperature pyrolysis, which are generally carried out in flame reactors

Safety opportunities for the synthesis of metal nanoparticles and short-cut approach to workplace risk evaluation

Notwithstanding the extensive use of engineered nanomaterials in various industrial and research settings, the impact of nanotechnology on the environment and its safety implications on the industrial production are still a challenging task. To date, the databases about nano-toxicology have a limited amount of information to establish suitable and widely accepted workplace safety regulations, both in relation with the toxicological/hazardous properties, lifecycle assessment, potential exposure pathways and the actual estimation of the number of workers exposed. Application of nano-materials in the process industries became an everyday practice in the last decade. However, the potential health hazard in producing, processing and using them has not been known exactly, yet. Accordingly, evaluating the hazard and calculating risk in their application leads to safer usage. Additionally, the development of cleaner production routes for nano-materials also contributes to minimizing the risk during their production. This paper introduces a critical discussion on cleaner and inherent safer approaches to the chemical synthesis of metal nanoparticles and outlines two novel synthesis processes for nano bismuth, a semimetal widely exploited in heterogeneous catalysis, microelectronic and thermoelectric applications, magnetic field sensors etc. The methods for Bi nano synthesis, which are inherently much safer, are subsequently analysed by a short-cut tool offering a semi-quantitative estimation of the hazards for workers employed in the given research environment, starting from the concepts borrowed by the layer of protection analysis. Additionally, the screening tool, by comparing the hazardous character of processes, can help choosing the safer, cleaner and more eco-friendly one

Large scale carbon dioxide release: Short-cut analytical modelling and application

The ongoing development of CCS applications and installations at large scale involves the need of improving the knowledge of connected hazards resulting from accidental loss of containments, or intentional events. In fact, a massive release of CO2 can have catastrophic consequences for humans: the processes determining the hazards posed by accidental releases of CO2 from pressurized systems are complex, due to the thermodynamics of the outflow, with changes of phase, followed by the dispersion of the cold heavy gas. In this paper, we explore a peculiar scenario connected to a massive release of carbon dioxide and following accumulation driven by negative buoyancy effect under semi confined conditions, either due to low wind and natural complex orography, or to the presence of geometrical complications. The paper sets out a preliminary analytical model, developed under simplifying but conservative hypotheses, which can be conveniently adopted at least at the early stage of the evaluation process or for establishing emergency procedures defining critical distances and possible man exposure to the hazardous dose