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Aérosols semi-volatils
De l'identification au prélèvement Des études récentes concernant les aérosols semi-volatils ont révélé des interactions entre les particules et les vapeurs. Encore faut-il être capable d'identifier le caractère semi-volatil d'une substance pour développer une méthode de prélèvement et d'analyse prenant en compte les deux phases, particulaire et vapeur. Cet article a pour but de donner une définition adaptée de ce qu'est un aérosol semi-volatil et d'appliquer...
Evaluation of the DRIFT gas dispersion model version 3.6.4
The Health and Safety Executive (HSE) uses gas dispersion modelling in its assessment of the hazards and risks posed by toxic and flammable substances stored at major hazards sites. To update its dispersion modelling capability, HSE recently commissioned ESR Technology to develop a new version of the gas dispersion model DRIFT (Dispersion of Releases Involving Flammables or Toxics). The new version of the model, DRIFT Version 3 (DRIFT 3), includes a significant number of modelling enhancements over the version of DRIFT previously used within HSE (DRIFT 2.31). These include the extension of the...
A case-control study of airways obstruction among construction workers
Background: While smoking is the major cause of chronic obstructive pulmonary disease (COPD), occupational exposures to vapors, gases, dusts, and fumes (VGDF) increase COPD risk. This case-control study estimated the risk of COPD attributable to occupational exposures among construction workers. Methods: The study population included 834 cases and 1243 controls participating in a national medical screening program for older construction workers between 1997 and 2013. Qualitative exposure indices were developed based on lifetime work and exposure histories. Results: Approximately 18% (95%CI ...
Métrologie en temps réel de substances chimiques au poste de travail
Intérêts et limites Les gaz, vapeurs et aérosols peuvent aujourd'hui être mesurés en temps réel à un poste de travail. Les techniques utilisées sont nombreuses et, pour certaines, de plus en plus simples à utiliser. Après avoir présenté les enjeux liés à l'utilisation de ces techniques pour la sécurité et la santé au travail, cet article en explique les intérêts et les limites par type de substances chimiques (gaz/vapeur et aérosols). Source: http://www...
Consultation on monitoring of water-miscible metalworking fluid (MWF) mists
The aim of this research was to examine metal working fluid (MWF) exposure limits and guidance set by other countries, summarise studies and investigations that examined water-miscible MWF mist as well as new techniques to monitor mist. Source: http://www.hse.gov.uk/research/rrhtm/rr1044.htm
Aerosol Transmission of Infectious Disease
Objective: The concept of aerosol transmission is developed to resolve limitations in conventional definitions of airborne and droplet transmission. Methods: The method was literature review. Results: An infectious aerosol is a collection of pathogen-laden particles in air. Aerosol particles may deposit onto or be inhaled by a susceptible person. Aerosol transmission is biologically plausible when infectious aerosols are generated by or from an infectious person, the pathogen remains viable in the environment for some period of time, and the target tissues in which the pathogen initiates infection...
Exposure to airborne particles and volatile organic compounds from polyurethane molding, spray painting, lacquering, and gluing in a workshop
Due to the health risk related to occupational air pollution exposure, we assessed concentrations and identified sources of particles and volatile organic compounds (VOCs) in a handcraft workshop producing fishing lures. The work processes in the site included polyurethane molding, spray painting, lacquering, and gluing. We measured total VOC (TVOC) concentrations and particle size distributions at three locations representing the various phases of the manufacturing and assembly process. The mean working-hour TVOC concentrations in three locations studied were 41, 37, and 24 ppm according to photo...
Optimisation de SATURISK, l’outil de calcul du temps de service des cartouches de protection respiratoire contre les vapeurs organiques
L'exposition des travailleurs aux solvants, ou plus largement aux vapeurs organiques, doit être maîtrisée sinon maintenue en deçà des valeurs limites réglementaires. Lorsque l'ensemble des mesures administratives, d'ingénierie et de protection collective ne permet pas d'atteindre des niveaux d'exposition sans danger pour la santé, les travailleurs concernés doivent être équipés d'appareils de protection respiratoire (APR). En l'absence de situations de danger immédiat pour la vie...
Chemical Vapour Deposition In The Semiconductor Industry
This Organisation for Economic Co-operation and Development (OECD) Emission Scenario Document (ESD) is intended to provide information on the sources, use patterns, and potential release pathways of chemicals used as chemical vapour deposition (CVD) precursors in the semiconductor industry. The document presents standard approaches for estimating environmental releases and occupational exposures, and discusses the typical engineering controls used to mitigate exposure to CVD precursors. Source: http://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=ENV/JM/MONO(2015)5&doclanguage...
L’effet de bâtiments en amont et en aval sur la dispersion des effluents
Une approche axée sur la mécanique des fluides numérique (CFD) La prédiction de la dispersion des émissions polluantes de cheminées de toit en milieu urbain est extrêmement complexe, tout particulièrement en présence de bâtiments voisins. Le comportement du panache dépend des caractéristiques du vent, mais il est aussi lourdement influencé par l'environnement. Il se peut ainsi que les effluents émis par une cheminée de toit se réintroduisent dans le bâtiment émetteur ou...
Étude en soufflerie de l’effet des bâtiments adjacents sur la dispersion en champ proche des émissions polluantes de cheminées de toit
La dispersion des polluants des émissions de cheminées de toit dans la couche limite est fortement influencée par la présence de bâtiments avoisinants et la topographie locale. Il est donc très difficile d'évaluer précisément les concentrations dans le panache sur différentes surfaces de bâtiments. Les polluants émis par une cheminée de toit peuvent présenter des risques pour la santé des occupants des bâtiments s'ils se réintroduisent dans le bâtiment duquel ils émanent...
Standardisation of the measurement of capture efficiency of on-gun extraction for welding
The inhalation of welding fume is recognised as being a real threat to workers' health due to the development of occupational illnesses such as welding fume fever and asthma. Local exhaust ventilation (LEV) is an effective method to control worker exposure to welding fume and previous work has indicated the merit of the use of on-gun extraction systems. The aim of the present study was to improve and refine the existing on-gun extraction methodology and has resulted in the development of two alternative methods for measuring the efficiency of on-gun fume extraction systems. There are distinct...
Biological Effects of Emissions From Resistance Spot Welding of Zinc-Coated Material After Controlled Exposure of Healthy Human Subjects
Objective: Do emissions from a resistance spot welding process of zinc-coated materials induce systemic inflammation in healthy subjects after exposure for 6 hours? Methods: Twelve healthy male subjects were exposed once for 6 hours either to filtered ambient air or to welding fume from resistance spot welding of zinc-coated material (mass concentration approximately 100 μg m−3). Biological effects were measured before, after, and 24 hours after exposure. Results: At the concentrations used in this study, however, the suspected properties of ultrafine particles did not lead to systemic...
Relationship Between Welding Fume Concentration and Systemic Inflammation After Controlled Exposure of Human Subjects With Welding Fumes From Metal Inert Gas Brazing of Zinc-Coated Materials
Objectives: It has been shown that exposure of subjects to emissions from a metal inert gas (MIG) brazing process of zinc-coated material led to an increase of high-sensitivity C-reactive protein (hsCRP) in the blood. In this study, the no-observed-effect level (NOEL) for such emissions was assessed. Methods: Twelve healthy subjects were exposed for 6 hours to different concentrations of MIG brazing fumes under controlled conditions. High-sensitivity C-reactive protein was measured in the blood. Results: For welding fumes containing 1.20 and 1.50 mg m−3 zinc, high-sensitivity C-reactive protein...
Risk assessment for VCE scenario in an aerosol warehouse
In 2006, Dr Graham Atkinson of HSL was asked by HSE to review the risks from fires in large aerosol stores (Atkinson, 2007). Atkinson reviewed incident statistics and reports and concluded that the greatest risk to people from such fires was from explosions, not from the fire itself. He postulated a vapour cloud explosion (VCE) mechanism, whereby a fire of material elsewhere in the warehouse from the aerosols could give rise to a hot air layer close to the ceiling. Aerosols stored close to the ceiling could then fail and release their flammable contents, but not be immediately ignited by the fire...
Vapour cloud formation
Experiments and modelling Hazard analysis for overfilling of a tank with a volatile liquid is a complex and important problem but (prior to the Buncefield incident) had not been the subject of significant research effort. Since the incident HSE has sponsored a programme of experimental and modelling research to investigate the technical issues involved and develop methods of analysis. The objective is that HSE, and industries responsible for filling tanks, will be in a position to agree on a reliable method to determine the character of the vapour cloud generated in the event of an overfill. This...
Good control practice for workers' exposure to gases in landfill - Sampling and measurement report-RR870
Gases generated by decomposition of landfill contain, principally, methane and carbon dioxide, but may also contain hazardous concentrations of trace components. This project gathered information on the potential exposure of workers to these trace components during specific types of tasks, to provide evidence to develop guidance on good practice for the control of exposure. The study was conducted at six land fill sites identified as having the potential to generate high concentrations of three representative trace components, vinyl chloride, hydrogen sulphide and benzene. Comparisons of personal...
Exposition aux bioaérosols dans deux milieux professionnels
Les cabinets de dentistes et les cultures de concombres et tomates L'exposition aux bioaérosols (1) (endotoxines, bactéries et spores de champignons en suspension dans l'air) et les problèmes de santé qui en découlent sont bien connus dans certains milieux professionnels (station d'épuration des eaux usées, élevages d'animaux, traitements des déchets organiques, travailleurs du bois, récolte et manutention des céréales, agriculture…). Cependant, les études avec investigations des concentrations...
LNG source term models for hazard analysis
A review of the state-of-the-art and an approach to model assessment In 2006, the Health and Safety Laboratory (HSL) undertook a research project to develop tools for the National Fire Protection Agency (NFPA) Liquefied Natural Gas Technical Committee to evaluate liquefied natural gas (LNG) dispersion models. The work was commissioned by the Fire Protection Research Foundation (FPRF) and delivered a Model Evaluation Protocol (Ivings et al., 2007) which included a checklist of model evaluation criteria and a structure for complete model evaluation. A partial evaluation of some common current dispersion...
Bioaerosol emissions from waste composting and the potential for workers’ exposure
Composting organic waste is an important component of the waste management process in the UK and the strategy to reduce waste to landfill, and as a result there has been an increase in the number of commercial composting operations. Microbiological activity is fundamental to the composting process, therefore any handling of composting material is likely to make airborne significant quantities of those micro-organisms (referred to as bioaerosols). Workers mechanically handling compost on these sites may therefore be at risk of considerable exposure to bioaerosols depending on their work task, their...
Évaluation analytique de la dispersion des émissions de cheminées de toit sur les bâtiments
« Dispersion » permet de décrire la façon dont les effluents des cheminées ou d'autres émissions des bâtiments sont transportés et dilués par le vent soufflé à travers un regroupement de bâtiments ou ses environs immédiats. La pollution atmosphérique est extrême lorsque l'air présente un niveau de pollution excessif pendant plusieurs heures ou plusieurs jours, et il peut en résulter un grand inconfort, des maladies et même des décés chez les personnes les...
Review of FLACS version 9.0
Dispersion modelling capabilities FLame ACceleration Simulator (FLACS) is a commercial Computational Fluid Dynamics (CFD) code developed and marketed by Global Explosion Consultants (GexCon), based in Bergen, Norway. The software has been developed to model the dispersion and combustion of flammable liquids, gases and dust clouds in open and bounded geometries. The first version of FLACS, released in 1986, was developed by CMI (Christian Michelsen Research Institute). CMI continued the development of FLACS until 1992 at which time its development was passed to CMR (Christian Michelsen Research...
Automated system for indicating spray clearance times of MVR spray booths/rooms
This report describes the design and assembly of an automated device that will alert sprayers of isocyanate based paints of the presence of spray mist inside paint spray booths /rooms used in the motor vehicle repair (MVR) and other industries. Source: http://news.hse.gov.uk/2009/10/21/rr742-an-automated-system-for-indicating-spray-clearance-times-of-mvr-spray-booths-and-rooms/?rss=Research

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