The BZ Series of Horizontal Laminar Flow Hoods are designed for the handling of materials in a sterile working environment. The work area is continuously bathed with positive pressure ISO 5/Class 100 horizontal laminar flow air that has passed through a High Efficiency Particulate Air (HEPA) filter. This filter removes organisms and particulates 0.3 micron in size with an efficiency of 99.99%. The laminar airflow principle consists of moving individual streams of unidirectional, ultra-clean air along parallel lines with minimal turbulence. The HEPA filter is positioned in the rear of the work area and is protected by a removable, perforated metal diffuser.