Aerosols in the microbiology laboratory

The control of microbial aerosols is the major driver in the design of microbiological containment laboratories. The provision of a negative-pressure laboratory area with a high efficiency particulate air (HEPA) filtered exhausted ventilation system is intended to prevent the escape of infectious aerosols from the facility. The use of directional airflow within open-fronted safety cabinetry is designed to prevent the release of any aerosols from the working area of the cabinets. Class III safety cabinets and isolator systems provide physical barriers between the operator and activity while maintaining negative pressure and high airflows, with HEPA filtration to prevent the release of aerosols. As a last resort, respiratory protection is used to prevent the exposed worker from inhaling the infectious agent. Yet, the average microbiologist may have only a limited understanding of the processes that generate aerosols in the laboratory and may have little knowledge of how effective preventative equipment and processes are.