Laminar flow clean benches (also known as laminar flow hoods) provide an aseptic space to work with a product or specimen without contaminating it with particulates such as microorganisms. Laminar flow clean benches provide no protection for the user or the environment as airflow is directed out of the cabinet. If chemically hazardous or infectious materials are going to be used in the laminar flow hood, a biological safety cabinet is required.
A vertical laminar flow clean bench draws air from under the hood, filters it with a high-efficiency particulate air (HEPA) filter, and then forces the air down across the workspace and out the hood at the user. A vertical laminar flow hood is useful for parts assembly, to house processing equipment, or to pour agar plates, for example. The workspace of a horizontal laminar flow clean bench is bathed in a HEPA-filtered horizontal laminar airflow, and is often used for clinical or pharmaceutical applications, or whenever a sterile, particulate-free environment is needed.