Two and three foot Purifier® Vertical Clean Benches are for plant tissue culture and media plate preparation under ISO Class 5 (formerly Class 100) conditions to prevent airborne contamination. Because the bench does not provide user protection, it should not be used in conjunction with biohazardous material, toxins or radionuclides. During operation, room air is drawn through a prefilter in the top of the cabinet to trap large particles. Then, the air flows through a 99.99% efficient HEPA filter and is projected vertically over the work area. Indicator lights monitor differential pressure across the HEPA-filter. Glare-free, fluorescent lighting is located outside the contaminated work area. Light and blower switches are located on the front of the cabinet, within easy reach of the operator.