Air borne contaminations are in solid, liquid and gas phases. In ventilation sector, for contamination filtration generally particle filters are used and these particle filters can filter only solid particles. Liquid phase contaminations are filtered by mist eliminators or condensing equipments, while gas contaminations are filtered by chemical filters.

Gas phase filtration or chemical filters are used in industrial and water treatment facilities for odor control and equipment-process reliability, in commercial buildings to increase indoor air quality (IAQ 62.1) and energy saving.