3D printing, a type of additive manufacturing (AM), is a rapidly expanding field. Some adverse health effects have been associated with exposure to printing emissions, which makes occupational exposure studies important. There is a lack of exposure studies, particularly from printing methods other than material extrusion (ME). The presented study aimed to evaluate measurement methods for exposure assessment in AM environments and to measure exposure and emissions from four different printing methods [powder bed fusion (PBF), material extrusion (ME), material jetting (MJ), and vat photopolymerization] in industry. Structured exposure diaries and volatile organic compound (VOC) sensors were used over a 5-day working week. Personal and stationary VOC samples and real-time particle measurements were taken for 1 day per facility. Personal inhalable and respirable dust samples were taken during PBF and MJ AM. The use of structured exposure diaries in combination with measurement data revealed that comparatively little time is spent on actual printing and the main exposure comes from post-processing tasks. VOC and particle instruments that log for a longer period are a useful tool as they facilitate the identification of work tasks with high emissions, highlight the importance of ventilation and give a more gathered view of variations in exposure. No alarming levels of VOCs or dust were detected during print nor post-processing in these facilities as adequate preventive measures were installed. As there are a few studies reporting negative health effects, it is still important to keep the exposure as low as reasonable.

Spridning av biocider från sanering av båtbottenfärg bestämdes experimentellt genom  att sanera båtar med sex olika metoder och mäta den spridda andelen bottenfärg.  Metoderna är vanligt förekommande i fritidsbåtshamnar och utförs vanligen av  båtägaren, dessutom utvärderades fackmannamässig blästring. Resultaten från de  olika  scenariona visar att det går att utföra sanering med många av de vanliga  metoderna slipning, skrapning, gelupplösning samt blästring och uppnå insamling av  mer än 98 % av färgen. Metoderna skiljer sig åt i andelen spridd färg men även i  svårighetsgrad i utförande samt hur robust de kan utföras med bibehållen låg spridning.  Faktorer som utförande, båt och färgtyp varierar stort vid implementering på det svenska båtbeståndet, vilket ger att det sannolikt är viktigare med rätt  riskminskningsmetoder än att rangordna saneringsmetoderna. Metoder som bildar torra  små partiklar vid borttagande av färgen är känsliga för att dessa färgpartiklar sprids  med vinden. Beräkningar av partiklars vindtransport visar att de partikelstorlekar som  bildas vid tex slipning och skrapning med lätthet kan spridas utanför en skyddande  marktäckning till den yttre miljön. Spridningen i ett sådant saneringsfall kan vara  mycket högt och kan i det närmaste bli fullständig om inte skyddsåtgärder vidtas.  Hantering av denna risk bör göras genom att, såsom i vissa av de utförda  experimenten, samla in partiklarna med sug, ha kontroll över vindhastigheten samt  kravställa utförandet, alternativt förbjuda metodiken.

Black Magic Dust - a Literature Study The spontaneous discoloration of indoor surfaces which occurs especially during the heating period has been intensively investigated in Sweden, Norway and Germany since the end of the 1970s. On the basis of earlier studies and this phenomenon, referred to as "spontan nedsvärtning" (sudden soiling, in Sweden), "Hekesot" (in Norway), "‘black dwellings’ or ‘black magic dust’ (BMD), was attributed to the presence of semi-volatile organic compounds (SVOCs) and their interaction with dust and particles. This report is an atempt to display litterature available today regardning the scientific knowledge so far.

Vi har gjort en begränsad litteraturundersökning kring fenomenet ”plötslig nedsvärtning” (som alltså avviker från normal, långsam försmutsning av ytor). Dessa olika forskningsrapporter pekar flera på en rad samverkande faktorer som verkar vara förutsättningar för sådan nedsvärtning, på norska benämnt ”Heksesot”, engelska ”Black Magic Dust” och tyska ”Schwarzen wohnungen”. Viktigast av dessa förutsättningar är (utan rangordning): • ”Färska” byggmaterial, dvs snart efter nybyggnad / renovering. • Låg ventilation / luftomsättning • Låg luftfuktighet (dvs mest vintertid) • Statisk uppladdning. (syntetiska mtrl, plaster etc) • Hög halt av tyngre organiska ämnen, delvis flyktiga, s k ”SVOC” • Hög halt av små luftburna partiklar (kondensationskärnor) • Köldbryggor (ger luftrörelser, s k termofores) • Levande ljus (eller andra sotkällor)

Observationer kring detta fenomen uppkom i slutet på 60-talet och har fortgått sedan dess med återkommande nya fall i framförallt nyproduktion av bostäder men även vid efter renoveringsarbeten. Rapporter belyser att under denna tid pågick stora förändringar i samhället både vad gäller bygg- och inredningsmaterial, boendevanor och ventilation, men även kring nya energikrav på nya bostäder som tillsammans kan utgöra en ny situation för innemiljön och skapade förutsättningar för att detta fenomen plötsligt kunde observeras.

Teorin kring svärtning beskrivs som bildandet av partiklar inom ett visst storleksområde (0,1–2,5 μm), skapade genom kondensering av halvflyktiga organiska ämnen (s k SVOC) i inneluften på små svävande partiklar, inklusive sotpartiklar. Storleksområdet på dessa bildade partiklar/aggregat gör att dessa kan sväva i luften länge, för att därefter avsättas på vissa ytor inomhus. Detta kan ge relativt snabb nedsvärtning inom timmar, dagar, veckor.

Studerade undersökningar pekar på att fenomenet kan minskas/elimineras genom följande: • Undvik aktiviteter som generar partiklar, t ex rökning, eldning av ljus. • Sörj för god ventilation. Om det inte är möjligt, utnyttja effektiva luftrenare med HEPA-filter, hög CADR för lokal luftrening • Använd lågemitterande byggprodukter, med låg andel SVOC • Undvik matlagning utan tillräcklig ventilation • Undvik heta ytor, t ex halogenlampor • Undvik kalla ytor / köldbryggor Dessa åtgärder kan var för sig eller tillsammans reducera förekomsten av svärtning signifikant.

One way to support the development of new safety practices in testing and field failure situations of electric vehicles and their lithium-ion (Li-ion) traction batteries is to conduct studies simulating plausible incident scenarios. This paper focuses on risks and hazards associated with venting of gaseous species formed by thermal decomposition reactions of the electrolyte and electrode materials during thermal runaway of the cell. A test set-up for qualitative and quantitative measurements of both major and minor gas species in the vented emissions from Li-ion batteries is described. The objective of the study is to measure gas emissions in the absence of flames, since gassing can occur without subsequent fire. Test results regarding gas emission rates, total gas emission volumes, and amounts of hydrogen fluoride (HF) and CO2 formed in inert atmosphere when heating lithium iron phosphate (LFP) and lithium nickel-manganese-cobalt (NMC) dioxide/lithium manganese oxide (LMO) spinel cell stacks are presented and discussed. Important test findings include the large difference in total gas emissions from NMC/LMO cells compared to LFP, 780 L kg−1 battery cells, and 42 L kg−1 battery cells, respectively. However, there was no significant difference in the total amount of HF formed for both cell types, suggesting that LFP releases higher concentrations of HF than NMC/LMO cells. © 2019 by the authors.

Biogas is a renewable energy source with many different production pathways and various excellent opportunities to use, for example as vehicle fuel (biomethane). Reliable analytical methodologies for assessing the quality of the gas are critical to ensure that the gas can technically and safely be used. An essential part of any procedure aiming to determine the quality is the sampling and the transfer to the laboratory. One of the greatest challenges is then to ensure that the composition of the sample collected does not change between the time of sampling and the analysis. The choice of the sampling vessel to be used must be made only after fully assessing its short-term stability. In this paper, the results from short-term stability studies in different vessels (cylinders, bags and sorbents) are presented for siloxanes, BTEX, halogenated hydrocarbons and sulfur compounds. Storage of dry gas at high pressure (> 6 MPa) appears to be a good alternative however it is currently challenging to find an optimal treatment of the cylinders for all species to be assessed in biogas/biomethane. At lower pressure, adsorption effects on the inner surface of the cylinders have been observed. The use of bags and sorbent tubes also shows limitation. No existing sorbent tubes are sufficiently universal as to trap all possible impurities and high boiling compounds may adsorbed on the inner surface of the bags walls. Moreover, the presence of water when storing biogas most certainly impacts the storage stability of compounds in most vessels. Using at least two sampling methods for a given compound and comparing results will allow taking into account the eventual effects of water vapour, and adsorption on the inner surface of the vessels.

Semi-volatile organic compounds (SVOCs) are indoor air pollutants that may have significant adverse effects on human health. Although emissions of volatile chemicals from building materials and consumer products are usually characterized in small chambers, few chamber studies have been conducted for SVOCs due to the challenges associated with analysis and the lack of validation procedures. There is an urgent need for a reliable and accurate chamber test method to verify these measurements. A reference method employing a specially-designed chamber has been developed and is undergoing extensive evaluation. A pilot inter-laboratory study (ILS) has been conducted with six laboratories performing chamber tests under identical conditions for di-2-ethylhexyl phthalate (DEHP). Results from this study showed inter-laboratory variations of 24% for DEHP emission rates, with closer agreement observed among intra-laboratory measurements for most of the participating laboratories. A mechanistic emission model fits well to the measured concentration profiles, demonstrating the feasibility of the proposed reference method to independently assess laboratory performance and validate SVOC emission tests.

The atmospheric environment inside and outside historical organs in several European regions is reported. In each region, comparisons were made between an instrument suffering organ pipe corrosion and an organ without reported corrosion problems. Concentrations of acetic acid (ethanoic acid), formic acid (methanoic acid), acetaldehyde (ethanal), formaldehyde (methanal) and other volatile organic compounds in the organ environment were determined using active sampling. Temperature and relative humidity were recorded. In addition, polished metal samples that mimic the material used in the historical organ pipes have been exposed in the organ wind systemsfor up to 22 months. High concentrations of acetic acid andformic acid vapours are present in the wind system of the corroded organs. Acetaldehyde and formaldehyde are also present in smaller amounts. The main source of acetic acid is the wood from which the wind system is built. In contrast, formic acid is generated in the church environment outside the wind system. The results show that the two organic acids play an important role in the atmospheric corrosion of organ pipes. It is suggested that the corrosion of lead pipes in historical organs can be effectively reduced by removing the sources of gaseous acetic acid and formic acid in the wind system and in the church environment.