Baghouse filters have traditionally been very effective in maintaining low dust emissions from industrial sources. The trend toward tighter and carefully monitored specifications continues however, in order to meet modern ambient air quality standards. Moreover, these standards are particle size specific and based on inhalable and respirable dust concentrations (PM10, PM2.5). The technology is therefore assessed with regard to options for lowering emission levels, such as tighter filter media, better filter houses, or smarter ways of operating them. Much of the underlying research was done in cooperation with the European Consortium on Filtration Technology in Karlsruhe. Gerhard Kasper is a professor of chemical engineering at the Karlsruhe Institute of Technology since 1996. Previously, he held various positions with Air Liquide Corp. in the United States, including Director of the Chicago Research Center from 1985 to 1992. Between 1988 and 2012 he was an editor of the Journal of Aerosol Science. A significant part of his research is on gas filtration, particle emission mechanisms from industrial sources and ultra-clean gas technol ... mehrogy, involving co-operations with many key industrial partners. In another area, he and his collaborators have contributed to the development of new gas-phase processes for tailoring the physical and chemical “structure” of submicron and nano-particles for applications in new materials. This work is always complemented by the development of better (and preferably on-line) methods of measuring inside processes and characterizing particulate systems.