21 CFR 113 of the Electronic Code of Federal Regulations (eCFR) defines aseptic processing and packaging as “the filling of a commercially sterilized cooled product into presterilized containers, followed by aseptic hermetical sealing, with a presterilized closure, in an atmosphere free of microorganisms”.  Environmental monitoring and control is essential to aseptic fill/finish processes producing food and pharmaceuticals. 

HEPA (high efficiency particulate air filters) filters and HEPA filter integrity are critical to air filtration systems in industries including pharmaceutical, semiconductor, food, and nuclear. HEPA filters are most effective when used at their rated airflow resistance and face velocity, and various standards have been implemented for certification and in-situ qualification testing of HEPA filters.

The covid-19 pandemic has generated an increased interest in airflow and cleaning the air.  Air cleaners, also referred to as air purifiers or sanitizers, use differing technologies including HEPA filtration, activated carbon filtration, ultraviolet (UV) germicidal irradiation, or multiple technologies such as filtration with UV disinfection.  The ASHRAE Position Document on Filtration and Air Cleaning provides information on these and other technologies.