Hepa Filter The HEPA absolute filters are used for filtration of incoming, outgoing and recirculation air in ventilation systems such as: Incoming Air: Clean Rooms, Operating Theatres, Laboratories, etc... Industrial Processes: Microelectronics, food industry, optics, pharmaceutical industry, fine chemistry, etc. Treatment of Dangerous substances: Asbestos, Metal dust, Bacteria, Viruses, Radioactive Particles. Astroven (Galvanized). Astroven (MDF).